Question

How many grams of Ca(NO3)2 can be produced by reacting excess HNO3 with 8.90 g of Ca(OH)2?

Answer 1

ANSWER

The mass of Ca(NO3)2 is 19.692 grams

STEP-BY-STEP EXPLANATION:

Given information

The mass of calcium hydroxide = 8.90g

Step 1: Write a balanced equation for the reaction

$Ca(OH)_2+2HNO_3\text{ }\rightarrow Ca(NO_3)_2+2H_2O$

From the above reaction, you will see that 1 mole of calcium hydroxide reacts with 2 moles of nitric acid to give one mole of calcium nitrate.

Step 2: Find the number of moles of calcium hydroxide using the below formula

$\text{mole = }\frac{\text{ mass}}{\text{ molar mass}}$

According to the periodic table, the molar mass of calcium hydroxide is 74.093 g/mol

$\begin{gathered} \text{mole = }\frac{8.90}{74.093} \\ \text{mole = 0.120 moles} \end{gathered}$

Step 3: Find the number of moles of calcium nitrate using a stoichiometry ratio

From the above reaction, you will see that 1 mole of calcium hydroxide reacts with 2 moles of nitric acid to give 1 mole of calcium nitrate.

Let x represents the number of moles of Ca(No3)2

$\begin{gathered} 1\text{ }\rightarrow\text{ 1} \\ 0.120\rightarrow x \\ \text{cross multiply} \\ 1\text{ }\times\text{ x = 1}\times0.120 \\ x\text{ = 0.120 moles} \end{gathered}$

Hence, the number of moles of Ca(NO3)2 is 0.120 moles

Step 4: Find the mass of ca(NO3)2 using the below formula

$\text{mole = }\frac{\text{ mass}}{\text{ molar mass}}$

According to the periodic table, the molar mass of Ca(NO3)2 is 164.1 g/mol

$\begin{gathered} 0.120\text{ = }\frac{mass}{164.1} \\ \text{cross multiply} \\ \text{mass = 0.120 }\times\text{ 164.1} \\ \text{mass = 19.692 grams} \end{gathered}$

Hence, the mass of Ca(NO3)2 is 19.692 grams