8.2 grams of calcium nitrate is decomposed by heating according to the equation2Ca (NO3 )2 _____  2CaO +4NO2 + O2Calculate the following:(a) Volume of nitrogen dioxide obtained at STP(b) Mass of CaO formed[Atomic weights: Ca –40 , N—14, O—16][4]

To solve this problem, we first need to understand the balanced chemical equation and the concept of mole ratios. The balanced chemical equation is:

2Ca(NO3)2 → 2CaO + 4NO2 + O2

This tells us that 2 moles of calcium nitrate decompose to form 2 moles of calcium oxide, 4 moles of nitrogen dioxide, and 1 mole of oxygen.

(a) Volume of nitrogen dioxide obtained at STP:

First, we need to calculate the number of moles of calcium nitrate in 8.2 grams. The molar mass of calcium nitrate [Ca(NO3)2] is 164 g/mol (40 for Ca, 28 for N, and 96 for O).

So, moles of Ca(NO3)2 = 8.2 g / 164 g/mol = 0.05 mol

From the balanced equation, we know that 2 moles of Ca(NO3)2 produce 4 moles of NO2. Therefore, 0.05 moles of Ca(NO3)2 will produce 0.05 * 2 = 0.1 moles of NO2.

At STP (Standard Temperature and Pressure), 1 mole of any gas occupies 22.4 liters. So, the volume of NO2 gas produced is 0.1 mol * 22.4 L/mol = 2.24 L.

(b) Mass of CaO formed:

From the balanced equation, we know that 2 moles of Ca(NO3)2 produce 2 moles of CaO. Therefore, 0.05 moles of Ca(NO3)2 will produce 0.05 moles of CaO.

The molar mass of CaO is 56 g/mol (40 for Ca and 16 for O). So, the mass of CaO produced is 0.05 mol * 56 g/mol = 2.8 g.