Question

4 grams of hydrogen and 32 grams of oxygen will combine to form:
36 grams of water
28 grams of hydroxide
32 grams of oxygen
36 grams of deuterium

multiple choice 1 point
in a chemical reaction, 4 grams of sodium must combine with how many grams of chlorine to produce 10 grams of table salt?
4 grams
6 grams
8 grams
10 grams

Explanation:

Step1: Apply law of conservation of mass

In a chemical reaction, the total mass of reactants equals the total mass of products.

Step2: Calculate product mass for hydrogen - oxygen reaction

4 grams of hydrogen and 32 grams of oxygen react. The total mass of reactants is $4 + 32=36$ grams. They form water according to the reaction $2H_2 + O_2=2H_2O$. So, 36 grams of water is formed.

Step3: Calculate mass of chlorine for sodium - chlorine reaction

Let the mass of chlorine be $x$ grams. Given 4 grams of sodium reacts to form 10 grams of table - salt (sodium chloride). Using the law of conservation of mass, $4 + x=10$. Solving for $x$, we get $x = 10 - 4=6$ grams.

Answer:

A. 36 grams of water
B. 6 grams