<h3>
Answer:</h3>
#a.2H2 + O2 → 2H2O
#b. 2S + 3O2 → 2SO3
#d. 2K + 2H2O → H2 + 2KOH
<h3>
Explanation:</h3>
- A balanced chemical equation is one that has equal number of atoms of each element on both sides of the equation.
In this case;
- 2H2 + O2 → 2H2O - is balanced since it has, 4 hydrogen atoms and 2 oxygen atoms on either sides of the equation.
- 2S + 3O2 → 2SO3, is balanced. It has 2 sulfur atoms and 6 oxygen atoms on both side of the equation.
- 2K + 2H2O → H2 + 2KOH, is balanced , 2 potassium atoms, 4 hydrogen atoms and 2 oxygen atoms on both side of the equation.
- On the other hand, the equations that are not balanced include;
- Li + Cl2 → LiCl
- 2Fe + Cu(NO3)2 → 2Cu + Fe(NO3)2
This is because the number of atoms of each element is not equal on both side of the equation/
D. Gravity is a dent in the fabric of space and time.
or
B. Radium is a radioactive element.
If 5.0 grams of KCl is dissolved in 500 ml of water, the concentration of the resulting solution will be 0.134M.
<h3>How to calculate concentration?</h3>
The concentration of a solution can be calculated by using the following formula;
Molarity = no of moles ÷ volume
According to this question, 5.0 grams of KCl is dissolved in 500 ml of water. The concentration is calculated as follows:
no of moles of KCl = 5g ÷ 74.5g/mol = 0.067mol
Molarity = 0.067mol ÷ 0.5L = 0.134M
Therefore, if 5.0 grams of KCl is dissolved in 500 ml of water, the concentration of the resulting solution will be 0.134M.
Learn more about concentration at: brainly.com/question/10725862
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