Question

Calcium hydride (CaH2) reacts with water to form hydrogen gas: CaH2(s) + 2H2O(l) → Ca(OH)2(aq) + 2H2(g) How many grams of CaH2 are needed to generate 45.0 L of H2 gas at a pressure of 0.888 atm and a temperature of 32 °C?

Answer 1

Solution Cat, C5) +24,06) —> CaCOH) aq) + 2H2g). for H₂ gas given Volume (VI = USL Pressure (P) = 0.888 atm Teruperature (t) = 32°C = (32+273 )k = 305k using equation PV = nRT | here n u the number of moles of H₂ gal R- gas constant = (0.0821 atmL I molk, n= 0.888 atyn x 45X - - 1,595 mole - 305k X 0.0821 atne of H₂ - molk Now from equation. 2 moles of H₂ il produced from 1 mole of Calt, 1.595 mole " " " IX 10595 mole 2 of Cath, = 0.797 moles of Now no. of males = gi Mass . Cat Molar Mass Muss = m (moles) x 42.09 (g/mol) = 0.791 x42009 (9) = 33.54g Hence 33.54 g of Cat₂ ů needed