Question

рассчитайте объём водорода (н.у), который может быть получен при действии избытка раствора соляной кислоты на 4,0 г кальция

Answer 1

Ca + 2HCl = CaCl2 + H2

n(Ca) = m/M = 4г/40г/моль= 0,1моль

По уравнению реакции n(H2) = n(Ca) = 0,1моль

V(H2) = n x Vm = 0,1моль х 22,4л/моль = 2,24л

Answer 2

Calculating the Volume of Hydrogen Gas Produced

To calculate the volume of hydrogen gas produced when an excess of hydrochloric acid reacts with 4.0 g of calcium, we can use the balanced chemical equation for the reaction between hydrochloric acid and calcium:

Ca + 2HCl → CaCl2 + H2

From the balanced equation, we can see that 1 mole of calcium reacts with 2 moles of hydrochloric acid to produce 1 mole of hydrogen gas.

Given that the molar mass of calcium is 40.08 g/mol and the molar mass of hydrogen is 1.008 g/mol, we can calculate the volume of hydrogen gas produced using the ideal gas law:

PV = nRT

Where: - P = pressure (at standard conditions, 1 atm) - V = volume - n = number of moles - R = ideal gas constant (0.0821 L·atm/mol·K) - T = temperature (at standard conditions, 273 K)

Calculation Steps

1. Calculate the number of moles of calcium using its molar mass. 2. Use the mole ratio from the balanced chemical equation to find the number of moles of hydrogen gas produced. 3. Apply the ideal gas law to calculate the volume of hydrogen gas at standard conditions.

Calculation

1. Number of moles of calcium: - Molar mass of calcium = 40.08 g/mol - Number of moles = Mass / Molar mass - Number of moles = 4.0 g / 40.08 g/mol - Number of moles = 0.0998 mol

2. Number of moles of hydrogen gas produced: - From the balanced chemical equation, 1 mole of calcium produces 1 mole of hydrogen gas. - Therefore, 0.0998 moles of calcium will produce 0.0998 moles of hydrogen gas.

3. Calculate the volume of hydrogen gas at standard conditions: - Using the ideal gas law: PV = nRT - At standard conditions, P = 1 atm, T = 273 K, and R = 0.0821 L·atm/mol·K - V = nRT / P - V = (0.0998 mol)(0.0821 L·atm/mol·K)(273 K) / 1 atm - V ≈ 2.18 L

The volume of hydrogen gas (at standard conditions) that can be produced when an excess of hydrochloric acid reacts with 4.0 g of calcium is approximately 2.18 liters.