Answer:
Petals are modified leaves that surround the reproductive parts of flowers. They are often brightly colored or unusually shaped to attract pollinators. Together, all of the petals of a flower are called corolla.
C2H6O2 is infinitely miscible(soluble) in water. Ethylene glycol is a nonelectrolyte that is used as antifreeze. What is the lowest possible melting point for engine coolant that is 30% ethylene glycol? The Kf for H20 is 1.86 C/m.
Answer:
The lowest possible melting point for engine coolant is -12.8°C
Explanation:
This is about colligative property about freezing point depression.
We think the data 30% as a %m/m. It means that 30 g of ethylene glycol are contained in 100 g of solution. Therefore, we have 70 g of solvent.
Formula for freezing point depression is:
ΔT = Kf . m . i
Where ΔT = Freezing T° of pure solvent - Freezing T° of solution.
Freezing T° of solvent = 0° (We talk about water)
Let's determine m (molality, moles of solute in 1kg of solvent)
70 g = 0.070 kg
30 g . 1 mol / 62.07 g = 0.483 moles
0.483 mol / 0.070 kg = 6.90 m
We replace data in formula:
0° - Freezing T° of solution = 1.86 °C/m . 6.90m . 1
As ethylene glycol is a nonelectrolyte, i = 1
Freezing T° of solution = - 12.8°C
Hi can anyone answer these two distance and time questions
A 3.5 kg iron shovel is left outside through the winter. The shovel, now orange with rust, is rediscovered in the spring. Its mass is 3.7 kg. How much oxygen combined with the iron?
Fe + O2 ⟶FeO2⟶FeO2,As we can see our compound is FeO2FeO2 which is a simple combination with the same stoichiometry, so we will just do a subtract operation : 3.7 kg - 3.5 kg $= 0.2 \ \text{kg} \Rightarrow 0.2\color{#4257b2}{0} $ kgkg (respecting significant figures rule).
What does iron and oxygen together mean?Rust is the result of an iron and oxygen interaction together:It's an ionic since it is made up of the a metal and something that is not a metal.
Iron may rust even without water?Without water, rust cannot develop.Iron pipes frequently rust on the inside due to water vapor condensation on the metal.Moisture facilitates the electrolyte required for the reaction iron take place, which expedites the rusting process.
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can bees really fly if so why
_____ unit is the most widely used system of units in both science and business
Explanation:
I think the answer is metric system of units
because it is the most widely used system of units and its use in both science and business.
give two example for desert plants and animals?
please mark as brainliest
Answer:
Plants : Cactus, tumbleweed
Animals : camel, fennec fox
Answer:
Desert plant - Cactus & Tumbleweed
Desert animal - Camel & Scorpion
In a competition, an athlete throws a discus though the air. What was the average speed of the discus if it traveled 107 meters over a time of 12 seconds?
Answer:
8.92 m/s
Explanation:
Distance covered = 107 m
Time = 12 s
Average speed = ?
The relationship between the parameters is given by;
Average speed = Distance covered / Time
Average speed = 107 / 12
Average speed = 8.92 m/s
Identifies at least one organism
that goes through photosynthesis
or respiration
Special thanks to anyone who answers this...
Answer:
94.74 moles of NO₂ are produced.
Explanation:
Given data:
Volume of oxygen gas = 3714 L
Temperature = 273 K
Pressure = 1 atm
Moles of NO₂ produced = ?
Solution:
Chemical equation:
4NH₃ + 7O₂ → 4NO₂ + 6H₂O
Number of moles of oxygen:
At STP one mole of any gas occupy 22.4 L volume. Thus, 3714 L gas contain,
3714 L× 1 mol / 22.4 L
165.8 mol
now we will compare the moles of oxygen and nitrogen dioxide.
O₂ : NO₂
7 : 4
165.8 : 4/7×165.8 = 94.74 mol
Thus, 94.74 moles of NO₂ are produced.
If 125.0g of nitrogen is reacted with 125.0g of hydrogen, what is the theoretical yield of the reaction? What is the excess reactant? What is the limiting reactant? Show your work.
The theoretical yield of the reaction : 151.64 g
The limiting reactant : N₂
The excess reactant : H₂
Further explanationReaction
N₂+3H₂⇒2NH₃
A method that can be used to find limiting reactants is to divide the number of moles of known substances by their respective coefficients(mol ratio), and the smaller become a limiting reactant
mass of N₂=125 g
mol N₂(MW=28 g/mol) :
[tex]\tt mol=\dfrac{mass}{MW}\\\\mol=\dfrac{125}{28}=4.46[/tex]
mass H₂ = 125 g
mol H₂(MW= 2 g/mol) :
[tex]\tt mol=\dfrac{125}{2}=62.5[/tex]
From the equation, mol ratio N₂ : H₂ = 1 : 3
Limiting reactant : N₂ : H₂ =
[tex]\tt \dfrac{4.46}{1}\div \dfrac{62.5}{3}=4.46\div 20.8[/tex]
N₂ : limiting reactant
H₂ : excess reactant
mol NH₃ based on limiting(N₂) (from equation N₂ : NH₃ = 1 : 2)
[tex]\tt mol~NH_3=\dfrac{2}{1}\times 4.46=8.92[/tex]
mass NH₃ (MW=17 g/mol) :
[tex]\tt mass=mol\times MW\\\\mass=8.92\times 17=151.64[/tex]
what is glycol .....
expalin with example
Answer:
glycol, any of a class of organic compounds belonging to the alcohol family; in the molecule of a glycol, two hydroxyl (―OH) groups are attached to different carbon atoms. The term is often applied to the simplest member of the class, ethylene glycol.
Explanation:
Answer:
Glycol, any of a class of organic compounds belonging to the alcohol family; in the molecule of a glycol, two hydroxyl (―OH) groups are attached to different carbon atoms. The term is often applied to the simplest member of the class, ethylene glycol.
How much mass of sodium chloride ( ) should be dissolved in water to make 1.5 L of 0.75 M aqueous solution? The molar mass of is 58.5 g.
Answer:
Mass = 65.8 g
Explanation:
Given data:
Mass of sodium chloride = ?
Volume of solution = 1.5 L
Molarity of solution = 0.75 M
Solution:
Number of moles of sodium chloride:
Molarity = number of moles / volume in L
By putting values,
0.75 M = number of moles = 1.5 L
Number of moles = 0.75 M × 1.5 L
Number of moles = 1.125 mol
Mass of sodium chloride:
Mass = number of moles × molar mass
Mass = 1.125 mol × 58.5 g/mol
Mass = 65.8 g
In a laboratory, 30. J of heat was added to a gas piston assembly as the piston did 75 J of work on its surroundings. Calculate E for this system
Answer:
-40J
Explanation:
E= -w+q
E= -75J+30J
E= -40J
Which statement best describes an example of selective breeding?
5
A. People control how plants or animals reproduce to get desired
traits.
OB. People use enzymes to cut DNA, copy it, and paste pieces of it
back together.
O. Viruses deliver new genes to a person's cells to treat a genetic
condition.
OD. Living things that do well in an environment pass on their genes to
offspring.
Answer:
Answer is A
Explanation:
this is because selective breeding means selecting plants or animals having desired characteristics and let them breed with each other to reproduce an offspring having desired characteristics from both parents.
Answer:
A
Explanation:
How do metals and non-metals for ions?
Answer:
Metal atoms and non-metal atoms do different things when they ionise. Metal atoms lose the electron, or electrons, in their highest energy level and become positively charged ions. Non-metal atoms gain an electron, or electrons, to become negatively charged ions.
Explanation:
A. 6750 J
B. 387 J
C. 1935 J
D. 3.50 J
Answer:
It was answer
A)1935J
Explanation:
An object at rest has equal forces acting on it. This can be described as a(n) ______ force.
Answer:
it would be balanced forces.
Explanation:
Balanced forces acting on an object do not change the objects motion.
25g of potassium nitrate are dissolved in 100g of water. What is the percent by mass of potassium nitrate?
Why does salt sprinkled on icy roads cause the ice to melt?
Answer:
The actual reason that the application of salt causes ice to melt is that a solution of water and dissolved salt has a lower freezing point than pure water. When added to ice, salt first dissolves in the film of liquid water that is always present on the surface, thereby lowering its freezing point below the ices temperature. Ice in contact with salty water therefore melts, creating more liquid water, which dissolves more salt, thereby causing more ice to melt, and so on.
A salt forms in the reaction of aluminum with chlorine. What is the most likely formula unit of this salt
Answer:
AlCl3
Explanation:
since the stable oxidation state of Aluminum is +3, and that of Chlorine is +1, then it will give such a formulae ✔️
why is the separation of waste rock before mining so important?
Answer:
because the minerals in the rock can't be used until they are separated
How many molecules of HCl would react with 1 mole of Mg0?
Mg0 +2HCI
MgCl, + H,0
Answer:
12.044 ×10²³ molecules of HCl
Explanation:
Given data:
Number of moles of MgO = 1 mol
Number of molecules of HCl react = ?
Solution:
Chemical equation:
MgO + 2HCl → MgCl₂ + H₂O
with 1 mole of MgO 2 moles of HCl are react.
Number of molecules of HCl react:
1 mole contain 6.022×10²³ molecules
2 mol × 6.022×10²³ molecules / 1 mol
12.044 ×10²³ molecules
For the nitrogen fixation reaction 3H2(g) + N2(g) = 2NH3(g),
Kc = 6.0 x 10-2 at 500°C. If 0.253 M H2 and 0.044 M NH3 are
present at equilibrium, what is the equilibrium concentration
of N2?
The equilibrium concentration of N₂ : 1.992
Further explanationGiven
Kc = 6.0 x 10⁻² at 500°C
0.253 M H₂ and 0.044 M NH₃
Reaction
3H₂(g) + N₂(g) = 2NH₃(g)
Required
The equilibrium concentration of N₂
Solution
Kc for the reaction :
[tex]\tt Kc=\dfrac{[NH_3]^2}{[H_2]^3[N_2]}\\\\0.06=\dfrac{0.044^2}{0.253^3\times [N_2]}\\\\(N_2]=1.992[/tex]
Copper carbonate (CuCO3) reacts with hydrochloric acid (HCl) according to this equation:
CuCO3(s) + 2HCl(aq) → CuCl2(aq) + H2O(l) + CO2(g).
Which statement correctly describes the substances in this reaction?
A.
Exactly one product and two reactants are either liquid or dissolved in water.
B.
Exactly one of the reactants is in a water-based solution, but none of the products are.
C.
The reactants include both a liquid and a gas.
D.
Exactly one reactant is a solid, and exactly one product is a gas.
E.
The products include a solid, a liquid, and a gas.
Answer: D. Exactly one reactant is a solid, and exactly one product is a gas.
Explanation: PLATO
In the given reaction, there is only one reactant in solid state, that is copper carbonate and one gaseous product carbon dioxide. Hence, option D is the correct statement.
What is copper carbonate?Copper carbonate is an ionic compound formed by the combination of copper metal and carbonate group. Copper metal loses two electrons to the carbonate group. It is a white powder and sparingly soluble in water.
The states of reactants and products in a reaction is represented in brackets with the chemical formula of each compound. The reaction in which all the reactants are in same phase is called homogeneous.
The given reaction is an example of heterogeneous replacement reaction. The reaction includes the combination of solid copper carbonate with aqueous HCl giving copper chloride solution and carbon dioxide gas. Thus, option D is correct.
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How many atoms are in this chemical formula? NaC2H3O2
Answer:
The answer is eight atoms.
According to the second law of energy, most energy is wasted in the form of ________
A. sound
B. heat
C. electricity
D. light
Describe one action that people can take to reduce the amount of petroleum or crude oil needed by the plastics facility
Answer:
Use bags that are not of plastic and that we can reuse.
Explanation:
To reduce the number of petroleum, people should use everyday things that do not have plastic in their composition. For example, drink water from a flask made of iron, take your mug to the coffee store or use cloth bags. These elements are not disposable, and we can use them multiple times, which leads to a reduction in the consumption of plastic products and the amount of petroleum needed for their production.
ammonium(NH4) react with chlorine then will we get ammonium chloride
Answer:
yes when ammonium(NH4) react with chlorine then will we get ammonium chloride
Explanation:
Pure chlorine gas may react vigorously with ammonia gas. An excessive mix of the two gases in air can produce hazardous compounds such as the explosive nitrogen trichloride. ... Chlorine reacts readily with ammonium hydroxide to form ammonium chloride, a relatively harmless compound.
how many electrons are in an atom that has 25 protons and has an ion charge of negative 3
Answer:
7
Explanation:
3x6=18 leavig 7 behind
Hree friends are talking about what they think causes shiny pennies to turn dull. Deandre says, "I think they turn dull because they're exposed to the air over time." Jamie says, "I think they turn dull because they get dirt on them from being dropped on the ground." Selina says, "I think there is dull metal inside the penny the entire time." Who do you agree with most and why?
Answer:
Deandre is correct.
Explanation:
When shiny pennies turn dull, due to getting rust. It gets cover with a layer of black or brown color on its surface on the exposure of air.
In this problem,
Deandre says, "I think they turn dull because they're exposed to the air over time." Jamie says, "I think they turn dull because they get dirt on them from being dropped on the ground." Selina says, "I think there is dull metal inside the penny the entire time.
Out of three friends, Deandre is correct. Shiny pennies turn dull because they're exposed to the air over time.