Question

Write the following reaction in the form of a word equation:

Sodium hydroxide reacts with calcium bromide to form calcium hydroxide and sodium bromide.

In $Ca{Br}_2$​ ​, determine the valency of calcium.

• A. Sodium hydroxide + calcium bromide = calcium hydroxide + sodium bromide
  
  Valency: 1
• B. Sodium hydroxide + calcium bromide $\to$ calcium hydroxide + sodium bromide
  
  Valency: 2
• C. Sodium hydroxide + calcium bromide $\leftrightarrow$ calcium hydroxide + sodium bromide;
  
  Valency: 2
• D. Sodium hydroxide + calcium bromide $\to$ calcium hydroxide + sodium bromide;
  
  Valency: 1

Answer 1

The correct option is B Sodium hydroxide + calcium bromide $\to$ calcium hydroxide + sodium bromide

Valency: 2

A word-equation shows change of reactants to products through an arrow placed between them. The reactants are written on the left-hand side with a plus sign (+) between them. Similarly, products are written on the right-hand side with a plus sign (+) between them. The arrowhead points towards the products, and shows the direction of the reaction.

The word equation for the given reaction will be written as:

Sodium hydroxide + calcium bromide $\to$ calcium hydroxide + sodium bromide.

In $Ca{Br}_2$, the valency of calcium is 2 and the valency of bromine is 1.