Answer:
Exothermic reactions feel hot
Endothermic reactions feel cool
Explanation:
In an exothermic reaction, heat is given out by the system. The energy of the reactants is greater than that of the products hence the excess energy is given off as heat. The reaction vessel feels hot.
In an endothermic reaction, the energy of products is greater than that of the reactants hence energy is taken into the system and the reaction vessel feels cool.
what is 19.0 ul in ml
what are the strengths in the bonds of potassium bromide
Answer: Potassium Bromide (KBr) The Ionic bond formed between Potassium and Bromine is created through the transfer of electrons from Potassium (metal) to Bromine (nonmetal).
Explanation: this type of structure departs strongly from that expected for ionic bonding and ... whose roots go back to Max Planck's explanation in 1900 of the properties of ... types of interactions between elementary particles (the strong force, the weak force, ...
Which element is classified as a noble gas?
Answer:
any of the seven chemical elements that make up Group 18 (VIIIa) of the periodic table. The elements are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn), and oganesson (Og). :)
Explanation:
Answer:
For edge, the answer is;
D. Xe
(Xenon)
Explanation:
edg- answers ;p
The boundary between cold and warm air masses is called a ____.
A.
front
B.
storm
C.
climate
D.
flood
What can the chemical formula tell us about a compound?
Answer:
A chemical formula tells us the number of atoms of each element that is in a compound. It contains the symbols of the atoms for the elements present in the compound as well as how many there are for each element in the form of subscripts.
Hope this helps! please mark me brainliest!
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32. A chemical reaction in which calcium carbonate CaCO3 is decomposed, results in the
production of two simpler compounds.
CaCO3
>CaO
+
CO2
? 9
28.00 g
21.97 g
What mass of calcium carbonate, to the nearest hundredth of a gram, is
decomposed in this reaction?
Answer:
Mass of calcium carbonate decompose 49g.
Explanation:
Given data:
Mass of CaO = 28.00 g
Mass of CO₂ = 21.97 g
Mass of calcium carbonate decompose = ?
Solution:
Chemical equation:
CaCO₃ → CO₂ + CaO
Number of moles of CO₂:
Number of moles = mass/molar mass
Number of moles = 21.97 g / 44 g/mol
Number of moles = 0.49 mol
Number of moles of CaO:
Number of moles = mass/molar mass
Number of moles = 28.00 g / 56.1 g/mol
Number of moles = 0.49 mol
Now we will compare the moles of CaCO₃ with CaO and CO₂ .
CO₂ : CaCO₃
1 : 1
0.49 : 0.49
CaO : CaCO₃
1 : 1
0.49 : 0.49
Mass of CaCO₃ decompose:
Mass = number of moles × molaer mass
Mass = 0.49 mol × 100.1 g/mol
Mass = 49 g
Answer:
CaO
Explanation:
Which of the following best support the function of electrical signals in the nervous system?
Each nerve cell is connected to the brain by electrical signals.
Nerve cells communicate with the brain by sending out electrical signals
Electrical signals keep nerve cells alive.
Electrical signals are used to get rid of waste produced in the nervous system.
Answer:
Each nerve cell is connected to the brain by electrical signals
Explanation:
Answer:
they said it above me
Explanation:
There are approximately 250 million passenger vehicles in the United States. If each is driven 25,000 km per year, calculate the total mass of CO, NOx and HC emitted in 1970 if all vehicles just meet the government standard at that time. Please find the standard values in textbook. (Please round up to 3 decimal points and use 'E' for exponent)
Answer:
CO = 1.320 x 10¹¹ Kg
NOx = 1.942 x 10¹⁰ Kg
HC = 1.592 x 10¹⁰ Kg
Explanation:
Given that;
there are approximately 250 million passenger vehicles
each is driven 25,000 km per year which is 15534.28 miles per year
In 1970, the vehicular emission norms are;
CO = 34 g/mile , NOx = 5 g/mile , HC = 4.1 g/mile
so emission of CO in 1970 is;
250000000 × 15534.28 × 34 g
= 1.320 x 10¹⁴ g
= 1.320 x 10¹¹ Kg
Also, emission of NOx in 1970
250000000 × 15534.28 × 5 g
= 1.9417 x 10¹³ g
= 1.942 x 10¹⁰ Kg
emission of HC in 1970
= 250000000 × 15534.28 × 4.1 g
= 1.5922 x 10¹³ g
= 1.592 x 10¹⁰ Kg
Please help
What subatomic particle is not important when calculating the atomic mass of an atom
Answer:
Electrons
Explanation:
This is because electrons barely contribute to the mass so only protons and neutrons are added.
the density of an 18.0 solution of ammonium sulfate is 1.10g/ml. What mass of Ammonium sulfate is required to prepare 275ml of this solution
Answer:
Therefore, 54.45 g of Ammonium sulphate is required
Explanation:
Molar mass of ammonium sulphate, (NH₄)₂SO₄ = 132 g/mol
Since density of solution is 1.10 g/ml, a 1 mL solution has mass = 1.10 g
275 mL solution will have a mass = 275 * 1.10 = 302.5 g
Since the solution is 18% ammonium sulphate by weight,
mass of ammonium sulphate present in 275 mL solution = 302.5 * 18/100
mass of ammonium sulphate present in 275 mL solution = 54.45 g
Therefore, 54.45 g of Ammonium sulphate is required
Concentration data is commonly monitored during a reaction to determine the order with respect to a reactant. Consider the types of observations listed, and determine which order is likely for that reactant. Assume all other factors are held constant.
1. An increase in the concentration of the reactant in solution causes the reaction rate to increase exponentially.
a. first order
b. second order
c. zero order
2. The reaction rate increases in direct proportion to the concentration of the reactant in solution.
a. first order
b. second order
c. zero order
3. The reaction rate is constant regardless of the amount of reactant in solution.
a. first order
b. second order
c. zero order
Answer:
1) first order
2) second order
3) zero order
Explanation:
The curve of a first order reaction shows it to be exponential. In fact for a first order reaction, the concentration at a time t is an exponential function;
[A]t= [Ao] e^-kt
Where
[A]t = concentration at time =t
[Ao]= initial concentration
k= rate constant
t= time
For a second order reaction, the rate of reaction is directly proportional to the concentration of reactants.
For zero order reactions, rate of reaction is independent of concentration hence rate = k(rate constant)
The concentration data has been required for the determination of the rate of reaction. Based on the concentration of reactant and product, the rate has been determined.
1. For the first-order reaction, there has been an exponential increase in the rate of the reaction with the increase in the reactant concentration. The rate has been dependent on the concentration of the reactant.
Thus the correct option is A.
2. Irrespective of the first-order kinetic, in the second-order reaction, the rate of reaction has been directly proportional to the concentration of the reactant in the solution.
Thus option B is correct.
3. The zero-order reaction has been independent of the concentration of the reactant. The rate of reaction has been constant with an increase in the reactant concentration.
Thus option C is correct.
For more information about the rate of reaction, refer to the link:
https://brainly.com/question/8592296
Which of these is the term for the rate of flow of energy in a circuit?
velocity
electricity
resistance
current
What is the mass in grams of 5.9 mol c8 h18
Answer:
mass = density × volume = 0.67 × 1.00 = 0.67 kg = 670 g. The molar mass of octane, C8H18, is 8 × 12.01 (C) + 18 × 1.008 (H) = 114.224.
Explanation:
SpongeBob noticed that his favorite pants were not as clean as they used to be and wonders how can he get them clean again? His friend Sandy told him that he should try using Clean-O detergent, a new brand of laundry soap she found at Sail-Mart. SpongeBob made sure to wash one pair of pants in plain water and another pair in water with the Clean-O detergent. After washing both pairs of pants a total of three times, the pants washed in the Clean-O detergent did not appear to be any cleaner than the pants washed in plain water.
1)What is SpongeBob’s question?
2)What is SpongeBob’s claim?
3)What is the independent variable?
4)What is the dependent variable?
Answer:
1) SpongeBob’s question is that "what would be the appropriate way to wash his favorite pants as they don't seem as clean as earlier"?
2) SpongeBob’s claim that Clean-O detergent is unable to wash the pants more cleaner as compared to plain water.
3) Independent variable in the given example is the quantity of Clean-O detergent and plain water as it can be changed or manipulated.
4) Dependent variable in the given example is the cleanliness of pants as it will be affected by the quantity of Clean-O detergent and plain water which is an independent variable.
Explain how plucking occurs
Answer:
plucking is usually extracting hair
Explanation:
example: pluck the chicken feathers
pluck my brows
is carried out in a flow reactor where pure A is fed at a concentration of 4.0 mol/dm3. If the equilibrium conversion is found to be 60%, (a) What is the equilibrium constant, KC if the reaction is a gas phase reaction? (Ans.: Gas: KC = 0.328 dm3/mol)
Answer:
0.328 mol/dm³
Explanation:
We have
I started this calculation from Rate's law.
Remember equilibrium constant has been given to be 60%
Our interest is Kc, that is the equilibrium constant.
Ca = 4(1-0.6)/1+(-0.5*0.6)
= 4-2.4/1-0.3
= 1.6/0.7
= 2.2857
Cb = 4x0.6/2(1+(-0.5*0.6))
= 2.4/2(0.7)
= 2.4/1.4
= 1.7143
Kc = Cb/Ca²
= 1.7143/2.2857²
= 1.7143/5.2244
= 0.328 mol/dm³
I have added an attachment showing earlier stages to the final answer
Which is true of both the rock cycle and the water cycle?
both occur mostly in the atmosphere
both occur mostly in the geosphere
both have no beginning and no end
matter is created by both of them
A
Because both occur mostly in the atmosphere
And If both happens in the atmosphere it makes it the only answer by default
The study of the rocks is called petrology.
The correct answer to the question is option B that is both occur mostly in the geosphere.
What is a geochemical cycle?A geochemical cycle is the pathway that chemical elements take in the surface and crust of the Earth. The term geochemical tells us that geological and chemical factors are all included.
According to the question, both water and the rocks are present on the land and go to the reservoir with the help of a process called leaching. The common passage for both the cycling island.
Hence, the correct answer is option B.
For more information about the geochemical cycle, refer to the link:-
https://brainly.com/question/1255220
How does ionic bond forms?
Answer:
Ionic bond, also called electrovalent bond, type of linkage formed from the electrostatic attraction between oppositely charged ions in a chemical compound. Such a bond forms when the valence (outermost) electrons of one atom are transferred permanently to another atom.
Explanation: i took the same test
Answer:
it forms where a metal element and a non metal element react together to form a now compound
Move the chemistry book down again so it's surface touches the physics book. Quickly move the chemistry book back and forth. What's different when motion is faster?
Answer:
The temperature of the physics book increases as the chemistry book slides across it.
Explanation:
from plato
The temperature of the physics book increasing as the chemistry book slides across it is the difference when motion is faster.
What is Temperature?This is defined as the degree of hotness or coldness of a body and it increases when there is more friction.
When motion is faster , there is an increase in friction and increase in thermal(heat) energy which leads to increase in temperature.
Read more about Temperature here https://brainly.com/question/2331658
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Express the following numbers in scientific notation:
872
Answer:
The number 872 would be written as,
8.72× 10²
Explanation:
Scientific notation is used to express the large value in short form.
The number in scientific notation have two parts.
First part:
The digits (decimal point will place after first digit)
Second part:
× 10 ( the power which put the decimal point where it should be)
For example the number 872 would be written as
8.72× 10²
Another example:
6324.4 in scientific notation will be written as = 6.3244 × 10³
What is another term for the limbic system?:
A. primitive brain
B. logical brain
C. gender center
D. memory center
Answer:
a
Explanation:
because the sytem it si locate at the bothe side
Which phrase describes the element carbon-14?
We know that carbon -14 is a radioactive isotope of carbon
It is used in carbon dating to know the age of different forms of dead organism including plants...
So it is used for estimating the age of sedimentry rocks which contains dead debris of plants and animals,
it can be produced from N14 by radioactive reaction of N-14 with neutron.
It is found in organisms
Answer:
Found in organisms remains.
Explanation:
Hope this helped
why ice melt into water
Particle motion in ice is __________than partlice motion in water.
1. faster
2. slower
3. the same
Answer:
1. Faster
Explanation:
I need help with 5 and 6
Finally, someone gave a clear photo.
Can someone help me with this chemistry I have attached?, just helping me understand these problems. Its moles and questions
The data table shows the number of pumpkin seeds that germinate at different temperatures. What is the median number of seeds that germinate at 24C?
A. 80.5 B. 82 C. 78.5 D. 80
Answer:
Explanation:
80
4. CHALLENGE Suppose you had a mixture of sand and small,
hollow beads. How might you separate the mixture?
I'm not sure if this is the answer but maybe oil.
"Calculate the pH of an aqueous solution at 25°C that is (a) 0.15 M in HCl. 0.82 (b) 3.7 M in HNO3. -0.57 (c) 6.9 × 10−4 M in HClO4."
Answer:
See explanation
Explanation:
The pH of a solution is defined as the negative logarithm of hydrogen ion concentration.
For HCl
pH= - log[0.15] = 0.82
For HNO3
pH= -log[3.7] = -0.57
For HClO4
pH= - log [6.9 × 10^-4] = 3.16
a water sample is found to have a cl- content of 100ppm as nacl what is the concentration of chloride in moles per liter
Answer:
The concentration of chloride ion is [tex]2.82\times10^{-3}\;mol/L[/tex]
Explanation:
We know that 1 ppm is equal to 1 mg/L.
So, the [tex]Cl^-[/tex] content 100 ppm suggests the presence of 100 mg of [tex]Cl^-[/tex] in 1 L of solution.
The molar mass of [tex]Cl^-[/tex] is equal to the molar mass of Cl atom as the mass of the excess electron in [tex]Cl^-[/tex] is negligible as compared to the mass of Cl atom.
So, the molar mass of [tex]Cl^-[/tex] is 35.453 g/mol.
Number of moles = (Mass)/(Molar mass)
Hence, the number of moles (N) of [tex]Cl^-[/tex] present in 100 mg (0.100 g) of [tex]Cl^-[/tex] is calculated as shown below:
[tex]N=\frac{0.100\;g}{35.453\;g/mol}=2.82\times 10^{-3}\;mol[/tex]
So, there is [tex]2.82\times10^{-3}\;mol[/tex] of [tex]Cl^-[/tex] present in 1 L of solution.