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klemol [59]
2 years ago
7

1. Which of the following best describes natural selection?

Chemistry
1 answer:
Shalnov [3]2 years ago
8 0

Answer:

D

Explanation:

according to Darwin, out of the vast no of individuals which compete for a place in the world, only those having advantageous variations survive and reproduce

You might be interested in
Mandelic Acid is an organic acid composed of carbon (63.15%), hydrogen (5.30%), and oxygen (31.55%). Its molar mass is 152.14 g/
Dafna1 [17]

Answer:

Empirical formula is C3H3O

Molecular formula C9H9O3

Explanation:

From the question given, we obtained the following data:

Carbon = 63.15%

Hydrogen = 5.30%

Oxygen = 31.55%

We can obtain the empirical and molecular formula by doing the following as illustrated in the attached file. Please see attachment for explanation.

3 0
3 years ago
Read 2 more answers
4 Na + O2 → 2 Na2O<br><br> 6.79 moles of O2 will react to form how many moles of Na2O?
Nataly_w [17]

Answer:

13.94moles of Na₂O

Explanation:

The balanced reaction expression is given as:

        4Na  +  O₂  →   2Na₂O

Given parameters:

Number of moles of O₂ = 6.97moles

Unknown:

Number of moles of Na₂O

Solution:

 To solve this problem;

            1 mole of O₂  will produce 2 moles of Na₂O ;

            6.97 moles of O₂ will produce 6.97 x 2  = 13.94moles of Na₂O

6 0
2 years ago
Aqua regia, a mixture of HCl and HNO₃, has been used since alchemical times to dissolve many metals, including gold. Its orange
marissa [1.9K]

Aqua regia is an oxidative mixture that is highly corrosive and is composed of hydrochloric acid and nitric acid. The Ea (rev) for the reaction is 3 kJ.

<h3>What is activation energy?</h3>

The activation energy is the minimum required energy by the reactant to undergo changes to form the product. The activation energy of the reverse reaction is given by the difference in the production state and transition state.

It is given as,

Ea (rev) = Ea (fwd) − ΔHrxn

Given,

ΔH° = 83KJ

Ea (fwd) = 86 kJ/mol

Substituting the values above as:

Ea (rev) = 86 - 83

= 3 kJ

Therefore, the activation energy of the reverse reaction is 3 kJ.

Learn more about activation energy, here:

brainly.com/question/14287952

#SPJ4

4 0
1 year ago
What will a balloon do to a cloth if its negatively charged
masya89 [10]

Answer:

This involves negatively charged particles (electrons) jumping to positively charged objects. When you rub the balloons against the fabric they become negatively charged. They take some of the electrons from the fabric and leave them positively charged.

Explanation:

Negative charges attract to positive charges. If a balloon is not rubbed with the wool cloth, it has an equal amount of negative to positive charges, so it will attract to a rubbed balloon. When both balloons are rubbed with the wool cloth, the both receive negative charges, so they will repel each other.

3 0
2 years ago
Consider the following balanced reaction. How many grams of water are required to form 75.9 g of HNO3? Assume that there is exce
Iteru [2.4K]

Answer:

10.85 g of water

Explanation:

First we write the balanced chemical equation

3NO_{2} +H_{2}O -->2HNO_{3} +NO

Then we calculate the number of moles of nitric acid produced

n(HNO3) = \frac{mass}{molar mass} =\frac{75.9g}{63.02g/mol}=1.2044 mol

According to the balanced equation, water needed in moles is always half the number of moles of HNO3 produced. So since we will produce 1.2044 mol of HNO3, we will need 0.6022 mol of water. Now to calculate what mass that is:

mass(water)=number of moles*molar mass=0.6022mol*18.02g/mol=10.85g

5 0
3 years ago
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