A sample of sodium reacts completely with 0.213 kgkg of chlorine, forming 351 gg of sodium chloride. What mass of sodium reacted?

The mass of sodium reacted is 138 grams

Explanation:

Firstly, the chemical reaction should be represented with a balance chemical equation. The chemical equation can be written as follows.

Na = sodium

Cl2 = chlorine gas

Na + Cl2 → NaCl

The balanced equation is

2Na(s) + Cl2(g) → 2NaCl(aq)

Atomic mass of sodium = 23 grams per mol

Atomic mass of chlorine = 35.5 grams per mol

From the chemical equation the molar mass are as follows

Sodium = 2 × 23 = 46 grams

Chlorine = 35.5 × 2 = 71 grams

Sodium chloride =  2 × 23 + 2 × 35.5 = 117 grams

if 46 grams sodium reacted to produce 117 grams of sodium chloride

? grams of sodium react to produce 351 grams sodium chloride

grams of sodium reacted = (351 × 46)/117

grams of sodium reacted = 16146/117

grams of sodium reacted = 138  grams

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e