Answer:
Heat is the process of something getting hot(temperatures going up). Cold is when something gets cold(temperature decreases).
Explanation:
A chemical reaction causes the chemical compositions of substances to change.
a. True
b. False
Answer:
True
Explanation:
A chemical change is otherwise known as a chemical reaction. A chemical change is characterized by the formation of new substances, evolution of heat and change in chemical composition of substances. The change in the composition of substances during a chemical change is the result of the making and breaking of chemical bonds during a chemical change.
A chemical change is not easily reversible because it involves changes in chemical composition of substances.
An example of a chemical change is the combination of sodium hydroxide and hydrochloric acid according to the reaction equation;
HCl(aq) + NaOH (aq) -----> NaCl(aq) + H2O (l)
We easily notice the change in the chemical composition of each of the substances involved in the reaction.
What will happen when these mutations can no longer be killed by
antibiotics?
Answer:
Antibiotic resistance happens when the germs no longer respond to the antibiotics designed to kill them. That means the germs are not killed and continue to grow. It does not mean our body is resistant to antibiotics.
Which three forces can affect an object without contact?
Answer:
gravity, magnetic, electrostatic
A student placed 2 drops of an unknown sample in a test tube and added 2 mL of ethanol to the test tube while mixing gently. They added 2 drops of potassium permanganate reagent to the test tube and mixed the contents of the test tube gently. The initial color was a deep purple but then changed to a yellow color which precipitates as a brown solid. What compound is most likely the unknown
Answer:
2-propanol
Explanation:
From the given information
2 drops of an unknown sample were said to be placed in a test tube followed by the addition of 2 ml of ethanol then gentle mixing. They then initiate a further addition of 2 drops of potassium permanganate reagent (KMNO₄) to the test tube and mixed the contents of the test tube thoroughly. After adding 2 drops of potassium permanganate reagent, the reagent oxidizes the secondary alcohols(2-propanol) to ketone(i.e acetone) and no further reaction will take place since there are no reactive C-H bonds left. The diagram attached below shows how the reaction proceeds.
- Explain why the term greenhouse effect is used to describe the theory of global
warming.
Does the greenhouse effect affect life on Earth? If yes, explain how?
What are the possible effects of a buildup of greenhouse gases in our atmosphere?
How many moles of CO2 are in 58.5 g of carbon dioxide?
4 points
2.72 mol CO2
1.07 mol CO2
3.42 mol CO2
1.83 mol CO2
5. What types of surfaces would result in greater friction?
Answer:
Rough and irregular surface
these surfaces tends a lot of friction
but on smooth surface there is least friction
hope it helps
PCR amplification utilizes ________ template to produce a ________ product. For this question, select the answer that best describes the process as a whole: the nature of the template you used (the starting template added to the reaction) and the nature of the final product produced in your PCR analysis that you ran out on a gel will apply here.
Answer:
Double-stranded/Double-stranded
Explanation:
The PCR which is popularly known as polymerase chain reaction is the technique that uses the single copy of DNA to make thousands or levels a huge number(in terms of millions) of duplicates of that DNA.
The PCR is a laboratory procedure that is utilized to make various duplicates of a section of DNA as depicted previously. It is an unmistakable strategy.
There are 3 fundamental advances in PCR:
Denaturing
Annealing
Extending
In denaturing measure requires warming of the double-stranded DNA template to isolate it into a solitary strand. Eventually, it resulted into a double-stranded item.
What features did you use to classify igneous rocks as extrusive or intrusive ?
Answer: Igneous rocks may be simply classified according to their chemical/mineral composition as felsic, intermediate, mafic, and ultramafic, and by texture or grain size: intrusive rocks are course grained (all crystals are visible to the naked eye) while extrusive rocks may be fine-grained (microscopic crystals) or glass.
Explanation: Hope this helped! :)
Answer:
Igneous rocks may be simply classified according to their chemical/mineral composition as felsic, intermediate, mafic, and ultramafic, and by texture or grain size: intrusive rocks are course grained (all crystals are visible to the naked eye) while extrusive rocks may be fine-grained (microscopic crystals) or glass ( ...
PLEASE HELP!!!
Some single displacement reactions involve one halogen replacing a less reactive halogen.
Cl2, replaces iodine in NaI, producing I2 and NaCl. Write the balanced single displacement reaction with the simplest whole number coefficients.
Do not include the states of the reactants or products.
Answer:
[tex]Cl_2+2NaI\rightarrow I_2+2NaCl[/tex]
Explanation:
Hello there!
In this case, according to the described chemical reaction, Cl2 replaces iodine in NaI in order to produce I2 and NaCl:
[tex]Cl_2+NaI\rightarrow I_2+NaCl[/tex]
It is possible to realize how chlorine replaces iodine in agreement with the single displacement reaction. Moreover, since chlorine and iodine atoms are not correctly balanced, we add a 2 in front of both NaI and NaCl in order to do so:
[tex]Cl_2+2NaI\rightarrow I_2+2NaCl[/tex]
Best regards!
The balanced single displacement reaction should be Cl2+2Nal→I2+2NaCl.
Balance single displacement reaction:The C12 should be replaced with the iodine in Nal for generating the 12 and NaCl.
Also, the chlorine should replace the iodine in the agreement along with a single displacement reaction. Also, the chlorine and the iodine atoms should not be rightly balanced.
Therefore, The balanced single displacement reaction should be Cl2+2Nal→I2+2NaCl.
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How does size affect weight?
(20 points, write at least 5 sentences answer pls thx!)
During a dry compression test, the first puff of the test shows 50 PSI and the maximum reading after 4 strokes is 150 PSI. This indicates A. that the cylinders are good. B. weak piston rings. C. a bad spark plug. D. a hole in the piston.
One of the basic engine-diagnostic procedures that can be run is an engine compression test. All of the cylinders must have the same compression for the engine to run smoothly. There are just three possible ways for air to leak out of an engine and cause compression loss.
Exhaust or intake valve Engine rings (or piston, if there is a hole) An engine's head gasketThe procedures for conducting a compression testThe engine should be warmed to its typical operating temperature before testing in order to achieve the best results. The following procedures should be followed for an accurate compression test:
STEP 1: Dispose of each spark plug. As a result, the engine can be turned up to the same speed. Label all spark plug wires accurately.STEP 2 is to block the throttle open. This enables the engine to pull in the most air possible. Additionally, this step guarantees reliable compression test results.STEP 3 After inserting a compression gauge into a spark plug hole, start the engine. Four compression strokes of engine cranking should be performed in total. A puffing sound is produced after each compression stroke.EXAMPLE-If the ultimate, maximum value is 150 PSI, for instance, the reading following the first puff should be greater than 75 PSI. Low first-puff readings could be a sign of weak piston rings.STEP 4 Keep track of the highest readings, then compare the outcomes.Learn more about compression test here https://brainly.com/question/13274092
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Write and balance the following equation:
zinc (II) nitrate + copper
→ copper (1) nitrate + zinc
Answer:
This reaction will not occur since copper is less reactive than zinc.
Explanation:
Since copper is located at a lower position in the reactivity series than zinc, there will be no displacement reaction if copper is put into zinc (II) nitrate solution.
Use the following balanced reaction to solve 1-3:
P4 (s) + 6H2 (g) → 4PH3 (g)
1. How many grams of Hydrogen gas (H2) will be needed to react with 20 grams of P4?
Answer:
1.96g H2
Explanation:
P4 = 123.9g/mol
H2 = 2.02g/mol
[tex]\frac{20g P_{4} }{1}[/tex] * [tex]\frac{1 mol P_{4} }{123.9g}[/tex] * [tex]\frac{6 mol H_{2} }{1 mol P_{4} }[/tex] * [tex]\frac{2.02g H_{2} }{1 mol H_{2} }[/tex] = 1.96g H2
is the sun the only star in our solar system
Answer:
Hey mate......
Explanation:
This is ur answer.......
The largest star, and indeed the only star in our solar system, is the sun. The sun is a bit under a million miles across. About 110 Earths put side by side would equal the size of the sun. The sun has 99.8 percent of the mass of our solar system.
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Two trials are run, using excess water. In the first trial, 7.8 g of Na2O2(s) (molar mass 78 g/mol) is mixed with 3.2 g of S(s). In the second trial, 7.8 g of Na2O2(s) is mixed with 6.4 g of S(s). The Na2O2(s) and S(s) react as completely as possible. Both trials yield the same amount of SO2(aq). Which of the following identifies the limiting reactant and the heat released, q, for the two trials at 298 K?
Limiting Reactant q
A. S 30. kJ
B. S 61 kJ
C. Na2O2 30. kJ
D. Na2S2 61 kJ
Answer:
The answer is "Option C".
Explanation:
Given equation:
[tex]2Na_20_2 (s)+S(s)+2H_2O \longrightarrow 4NaOH(aq)+SO_2(aq)[/tex]
[tex]\to \Delta H^{\circ}_{rxn} (298\ K) = -610 \frac{kJ}{mol}[/tex]
[tex]\to Na_2O_2 \ Mass = 7.8 \ g\\\\ \to Na_2O_2 \ Molar \ mass = 78 \frac{g}{mol}[/tex]
[tex]Na_2O_2[/tex] Has been the reactant which is limited since the two experiments are equal to[tex]Na_2O_2[/tex] for relationship between stress amounts.
[tex]Na_2O_2, n =\frac{Mass of Na_2O_2}{Molar mass of Na_2 O_2}=\frac{7.8 \ g}{78 \frac{g}{mol}} =0.1 \ mol \\\\q=\Delta H^{\circ}_{rxn} \times n = \frac{ -610 \ kJ}{ 2 \ mol \ Na_2 O_2} \times 0.1 \ mol \ Na_2O_2= 30.5 \ KJ\\\\[/tex]
Limiting reactant =[tex]Na_2O_2[/tex]
[tex]q=30.5 \ kJ \approx 30 \ kJ[/tex]
What is the concentration of a solution with a
volume of 2.5 liters containing 660 grams of
calcium phosphate Ca3(PO4)2 ?
Answer:
660gx Imol = 2.1278 mol 310.189 2.5L 1.85 m).
Explanation:
The number of moles of 660 grams of calcium phosphate is 2.127. Then the molarity of the solution of 2.5 liter volume is 0.85 M.
What is molarity ?Molarity is a common term used to express the concentration of a solution. It is the ratio of number of moles of solute particles to the volume of solution in liters. Hence, its unit is mol/L or molar.
The molarity of a solution is a colligative quantity as well as temperature dependent.
Given,
molar mass calcium phosphate, Ca₃(PO₄)₂ =310.18 g/mol
Then,
no.of moles of calcium sulphate in 660 g = 660 g/310.18 g/mol = 2.127 moles
volume of solution = 2.5 L
Molarity = no.of moles of solute/ volume of solution in L
M = 2.127 moles/ 2.5 L
= 0.85 M.
Therefore, the molarity of the given solution is 0.85 molar.
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what does pen mean?.
Answer:
P = protons
E = electrons
N = neutrons
remember protons and neutrons (protons are positive and neutrons are neutral as you can already tell by their names) are found at the centre of the nucleus (positive mass). Whilst the electrons (negative) orbit around the shells
Classify the following as either an element, compound, homogeneous mixture or
heterogeneous mixture:
milk
Answer:
HeterogeneousExplanation:
Milk seems to be homogeneous mixture but actually milk is a heterogeneous mixture and a colloid solution.WILL MARK B!
Check image
Will increase points but someone answer Because I have an exam please answer ASAP
Answer:
Bro don't cheat in online exams bro
How many grams of chlorine are required in order to consume 85g of
sodium?
2 Na +1 C12
+ 2 Naci
The cell wall regulates what enters and exits the cell? True or False
Answer:
True
Explanation:
Answer:No, the Cell Membrane does I'm pretty sure
Explanation:
Consider the reactivity of phenol, bromobenzene, toluene, and nitrobenzene toward electrophilic aromatic substitution.
The most reactive compound is:_____
because the _______ character of the ______ increases the rate of the reaction.
The least reactive compound is ______
because the _______ character of the ________ decreases the rate of the reaction.
Answer:
The most reactive compound is: Phenol because the electron donating character of the alcohol group increases the rate of the reaction.
The least reactive compound is nitrobenzene
because the electron withdrawing character of the nitro group decreases the rate of the reaction.
Explanation:
PHENOL-: Any of a group of organic compounds with a hydroxyl (OH) group bound to a carbon atom in an aromatic ring is known as phenol. The word phenol is also the basic name for its simplest member, monohydroxybenzene (C6H5OH), also known as benzenol or carbolic acid, in addition to being the common name for the entire family.ELECTRON DONATING CHARACTER-: Via the carbon atom it is bound to, an electron donating group (EDG) has the net effect of increasing electron density in a molecule. EDGs alter a molecule's reactivity by increasing electron density on neighboring carbon atoms: EDGs make nucleophiles stronger.ALCOHOL GROUP-:Each of a class of organic compounds that have one or more hydroxyl (OH) groups bound to an alkyl group's carbon atom (hydrocarbon chain)is called Alcohol. Alcohols are organic compounds of water [tex](H_2O)[/tex] in which one of the hydrogen atoms has been substituted by an alkyl group, which in organic structures is usually expressed by R.NITROBENZENE-:The organic compound nitrobenzene has the chemical formula [tex](C_6H_5NO_2)[/tex]. It's a pale yellow oil that's insoluble in water and smells like almonds. Greenish-yellow crystals form when it freezes. It is made on a wide scale as a precursor to aniline from benzene. It is sometimes used as a solvent in the laboratory, especially for electrophilic reagents.ELECTRON WITHDRAWING GROUP-: An electron withdrawing group (EWG) is a type of group that reduces electron density in a molecule by bonding to a carbon atom. EWGs alter a molecule's reactivity by reducing electron density on neighboring carbon atoms.NITRO GROUP-: The nitro group is one of the most widely used explosophores (functional groups that combine to form a compound explosive). In addition, the nitro group is a heavy electron-withdrawing group. CH bonds alpha (adjacent) to the nitro group may be acidic due to this property.If 4.0 g of helium gas occupies a volume of 22.4 L at 0 o C and a pressure of 1.0 atm, what volume does 3.0 g of He occupy under the same conditions?
Answer:
the volume occupied by 3.0 g of the gas is 16.8 L.
Explanation:
Given;
initial reacting mass of the helium gas, m₁ = 4.0 g
volume occupied by the helium gas, V = 22.4 L
pressure of the gas, P = 1 .0 atm
temperature of the gas, T = 0⁰C = 273 K
atomic mass of helium gas, M = 4.0 g/mol
initial number of moles of the gas is calculated as follows;
[tex]n_1 = \frac{m_1}{M} \\\\n_1 = \frac{4}{4} = 1[/tex]
The number of moles of the gas when the reacting mass is 3.0 g;
m₂ = 3.0 g
[tex]n_2 = \frac{m_2}{M} \\\\n_2 = \frac{3}{4} \\\\n_2 = 0.75 \ mol[/tex]
The volume of the gas at 0.75 mol is determined using ideal gas law;
PV = nRT
[tex]PV = nRT\\\\\frac{V}{n} = \frac{RT}{P} \\\\since, \ \frac{RT}{P} \ is \ constant,\ then;\\\frac{V_1}{n_1} = \frac{V_2}{n_2} \\\\V_2 = \frac{V_1n_2}{n_1} \\\\V_2 = \frac{22.4 \times 0.75}{1} \\\\V_2 = 16.8 \ L[/tex]
Therefore, the volume occupied by 3.0 g of the gas is 16.8 L.
The volume occupied by 3.0 g of He is mathematically given as
V2=16.8L
What volume does the 3.0 g of He occupy?Question Parameters:
If 4.0 g of helium gas occupies a volume of 22.4 L at 0 o C and a pressure of 1.0 atm, what volume does 3.0 g of H
Generally, the equation for the gas equation is mathematically given as
PV=nRT
When the reacting mass is 3g
n2=3/4
n2=0.75
Therefore
V1/n1=V2/n2
Where
n1=1
[tex]V2=\frac{22.4*0.75}{1}[/tex]
V2=16.8L
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The mass of a salt in grams that will dissolve in 100 mL of water.
____________ A solution that has dissolved the maximum amount of a compound at a given temperature. Any further addition of salt will remain undissolved.
_________ The product of the molarities of the dissolved ions, raised to a power equal to the ion's coefficient in the balanced chemical equation.
__________ A decrease in the solubility of an ionic compound as a result of the addition of a common ion.
__________ The maximum number of moles of a salt that will dissolve in 1 L of solution.
a. A decrease in the solubility of an ionic compound as a result of the addition of a common ion.
b. The mass of a salt in grams that will dissolve in 100 mL of water.
c. A solution that has dissolved the maximum amount of a compound at a given temperature. Any further addition of salt will remain undissolved.
d. The product of the molarities of the dissolved ions, raised to a power equal to the ion's coefficient in the balanced chemical equation.
e. The maximum number of moles of a salt that will dissolve in 1 L of solution.
Answer:
Solubility : The mass of a salt in grams that will dissolve in 100 mL of water
Saturated solution : A solution that has dissolved the maximum amount of a compound at a given temperature. Any further addition of salt will remain undissolved
Solubility product constant :The product of the molarities of the dissolved ions, raised to a power equal to the ion's coefficient in the balanced chemical equation
Common ion effect : A decrease in the solubility of an ionic compound as a result of the addition of a common ion
Molar solubility : The maximum number of moles of a salt that will dissolve in 1 L of solution
Explanation:
Solubility is expressed usually as the mass of solute per 100 grams or 100 ml of solvent.
Molar solubility of a solid is expressed as the concentration of the dissolved solid in a saturated solution.
Solubility product constant is defined as the equilibrium constant in which a solid ionic compound is dissolved to produce its ions in solution. It is represented as
The common-ion effect is the decrease in solubility of a sparingly soluble salt by the addition to the solution of a soluble compound with an ion in common with the precipitate.
Saturated solution is defined as the solution in which no more solute particles can be dissolved in the solvent.
when someone pours milk into this life what is the the role of the coffee
A. Salt
B solvent
C solute
D solution
Potassium chlorate, a common oxidizing agent in fireworks and matchheads, undergoes a solid-state disproportionation reaction when heated:
4KClO3 (s) ⟶ Δ3KClO4 (s) + KCl (s).
Use ΔHf ° and S° values to calculate ΔG_sys ° (which is ΔGrxn °) in kJ at 25°C for this reaction.
Answer:
Explanation:
[tex]\text{From the information given:}[/tex]
[tex]\text{The chemical reaction is : } 4 KClO_{3(s)} \to 3 KClO_{4(s)} + KCl_{(s)}[/tex]
[tex]\text{To find} \ \Delta G^0_{rxn}\ \text{using the formula}: \\ \\ \Delta G^0_{rxn} = \sum n_p \times \Delta _f G^0 (Products) - \sum n_R \times \Delta _fG^0 ( Reactants) \\ \\ where; n_p = \text{no of moles of products } \ and; \\ \\ n_R = \text{no of moles of reactants }[/tex]
[tex]\implies G^0_{rxn} = 3 \times \Delta _fG^0 [KClO_4{(s)}] + \Delta_fG^0[KCl_{(s)}] - 4 \times \Delta _f G^0 [ KClO_3 (s) ][/tex]
[tex]\Delta _fG^0 \ values \ at \ 25^0 \ C (298 \ K) are\ given \ as:\\\\ \Delta _fG^0 [KClO_4(s)] = -303.09 \ kJ \\ \\ \Delta _fG^0 [KCl(s) ] = - 409.14 \ kJ \\ \\ \Delta_f G^0 [KClO_3_{(s)}] = -296.25 \ kJ \\ \\ replacing \ the \ above \ values \ into \ equation (1) ; then:\\ \\ \\\Delta G^0_{rxn} = 3 *(-303.09) + (-409.14) - 4*(-296.25) \ kJ \\ \\ = (-909.27 - 409.14 + 1185) \ kJ \\ \\ = -133.41 \ kJ \\ \\ \mathbf{\Delta G^0_{rxn} = -133.4 \ kJ }[/tex]
The standard free energy change of the reaction is -133 kJ.
From the reaction equation, we have; 4KClO3 ⇄ 3KClO4 (s) + KCl (s). The standard free energy of formation of each specie is given below;
ΔG°f KClO3 = -296.35 kJ
ΔG°f KClO4 = -303.09 kJ
ΔG°f KCl = -409.14 kJ
Hence;
ΔG°rxn = [3(-303.09)] + ( -409.14)] - [(4( -296.35))]
ΔG°rxn = (-909.27) + (-409.14) - (-1185.4)
ΔG°rxn = -133 kJ
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atoms of which two elements have combined total of 23 protons
Answer:
sodium and magnesium
Explanation:
Use the following balanced reaction to solve 1-3:
P4 (s) + 6H2 (g) → 4PH3 (g)
How many grams of phosphorus trihydride will be formed by reacting 60 L of Hydrogen gas with an excess of P4?
Answer:
60.86 g of PH₃
Explanation:
We'll begin by calculating the number of mole of H₂ that will occupy 60 L. This can be obtained as follow:
22.4 L = 1 mole of H₂
Therefore,
60 L = 60 / 22.4
60 L = 2.68 mole of H₂.
Next, we shall determine the number of mole of PH₃ produced by the reaction of 60 L (i.e 2.68 mole) of H₂. This can be obtained as follow:
P₄ + 6H₂ –> 4PH₃
From the balanced equation above,
6 moles of H₂ reacted to produce 4 moles of PH₃.
Therefore, 2.68 moles of H₂ will react to to produce = (2.68 × 4)/6 = 1.79 moles of PH₃.
Finally, we shall determine the mass of 1.79 moles of PH₃. This can be obtained as follow:
Mole of PH₃ = 1.79 moles
Molar mass of PH₃ = 31 + (3×1)
= 31 + 3 = 34 g/mol
Mass of PH₃ =?
Mass = mole × molar mass
Mass of PH₃ = 1.79 × 34
Mass of PH₃ = 60.86 g
Thus, 60.86 g of PH₃ were obtained from the reaction.
Help this is for marks, who ever answers get brainliest
Answer:
Coal
Explanation:
thx for points :D
Answer:
Coal
Explanation:
your welcome<3