Question

Question:Deal with the following situation: You react chemical A with chemical B to make one product takes 100 g of A to react completely with 20 g B.What is the mass of the product?
a. less than 20 g
b. between 20 and 100 g
c. between 100 and 120 g
d. exactly 120 g
e. more than 120 g

Short answer

Answer

The mass is exactly 120 g. Option D is correct.

Step-by-step solution

Mass of the product is less than 20 g is false

There are 100 g of a completely reacts with 20 g due to their mass conservation law, the product’s mass equal to the reactant’s mass of product. It can be denoted as,

$100g\times 20g=120g$

When A does not react with B, mass of product should be less than 120 g. This is not correct.

Mass of the product is between 20 and 100 g

There are 100 g of a completely reacts with 20 g due to their mass conservation law, the product’s mass equal to the reactant’s mass of product. It can be denoted as,

$100g\times 20g=120g$

When A does not react with B, mass of product should be less than 120 g. This is not correct.

Mass of the product is between 100 and 120 g

There are 100 g of a completely reacts with 20 g due to their mass conservation law, the product’s mass equal to the reactant’s mass of product. It can be denoted as,

$100g\times 20g=120g$

When A does not react with B, mass of product should be less than 120 g. This is not correct.

 Step 4: Mass of the product is exactly 120 g

There are 100 g of a completely reacts with 20 g due to their mass conservation law, the product’s mass equal to the reactant’s mass of product. It can be denoted as,

$100g\times 20g=120g$

When A does not react with B, mass of product should be less than 120 g. This is correct.

Mass of the product is more than 120 g

There are 100 g of a completely reacts with 20 g due to their mass conservation law, the product’s mass equal to the reactant’s mass of product. It can be denoted as,

$100g\times 20g=120g$

When A does not react with B, mass of product should be less than 120 g. This is not correct.