Question

78 g of potassium reacted with 44.8 liters of chlorine. Calculate the amount and mass of the salt obtained. 2 mol; 74.5 g 1 mole; 74.5 g 1 mole; 149 g 2 mol; 149 g​

Answer 1

Ответ:

2K+Cl2=2KCl

n(K)=78/39=2mol

n(Cl)=44.8/22.4=2mol

n(KCl)=2*74.5=149g

2mol;149g

Answer 2

To calculate the amount and mass of the salt obtained, we first need to determine the limiting reactant. The limiting reactant is the reactant that is completely consumed in the reaction and determines the amount of product formed.

To find the limiting reactant, we need to compare the number of moles of potassium to the number of moles of chlorine.

Given: - 78 g of potassium - 44.8 liters of chlorine

To find the number of moles of potassium, we can use its molar mass: Molar mass of potassium (K) = 39.1 g/mol Number of moles of potassium = mass / molar mass Number of moles of potassium = 78 g / 39.1 g/mol = 1.997 moles (approximately 2 moles)

To find the number of moles of chlorine, we need to convert liters to moles using the ideal gas law: PV = nRT

Where: P = pressure (assume standard pressure, 1 atm) V = volume of gas n = number of moles R = gas constant (0.0821 L·atm/(mol·K)) T = temperature (assume room temperature, around 298 K)

Number of moles of chlorine = (pressure * volume) / (gas constant * temperature) Number of moles of chlorine = (1 atm * 44.8 L) / (0.0821 L·atm/(mol·K) * 298 K) = 1.95 moles (approximately 2 moles)

From the comparison, we can see that both reactants have the same number of moles. Therefore, neither potassium nor chlorine is in excess, and both will react completely.

The balanced chemical equation for the reaction between potassium and chlorine is: 2 K + Cl2 -> 2 KCl

From the balanced equation, we can see that 2 moles of potassium react with 1 mole of chlorine to form 2 moles of potassium chloride (KCl).

Therefore, the amount of salt obtained is 2 moles and the mass of the salt obtained is the molar mass of potassium chloride multiplied by the number of moles: Molar mass of potassium chloride (KCl) = 39.1 g/mol (K) + 35.5 g/mol (Cl) = 74.6 g/mol (approximately 74.5 g/mol)

Mass of the salt obtained = molar mass * number of moles Mass of the salt obtained = 74.5 g/mol * 2 mol = 149 g