Answer:
M₂ = 0.9 M
Explanation:
Given data:
Initial Volume = V₁ = 250 mL
Initial molarity = M₁= 3 M
Final volume = 850 mL
Final molarity = ?
Solution:
M₁V₁ = M₂V₂
M₂ = M₁V₁ /V₂
M₂ = 3 M × 250 mL / 850 mL
M₂ = 750 M / 850
M₂ = 0.9 M
Answer:
7.99 mol
Explanation:
Step 1: Given data
Molecules of chlorine gas: 4.81 × 10²⁴ molecules
Step 2: Calculate how many moles of chlorine gas corresponds to 4.81 × 10²⁴ molecules of chlorine gas
In order to convert molecules to moles, we will use Avogadro's number: there are 6.02 × 10²³ molecules of chlorine gas in 1 mole of molecules of chlorine gas.
4.81 × 10²⁴ molecules × (1 mol/6.02 × 10²³ molecules) = 7.99 mol
A neutral solution means we are having equal amount of H⁺ and OH⁻. As we know,
Kw = [H⁺] [OH⁻] ------ (1)
So, in order to calculate Kw we first need to calculate [H⁺] and [OH⁻],
As, pH = -log [H⁺]
Or,
[H⁺] = 10⁻ˣ ∴ x = pH = 7.61
Putting value, and solving
[H⁺] = 2.45 × 10⁻⁸
As, our system is neutral, so concentration of [OH⁻] is exactly equal to concentration of [H⁺]. Now, putting values of [H⁺] and [OH⁻] in equation 1.
Kw = [2.45 × 10⁻⁸] [2.45 × 10⁻⁸]
Kw = 6.00 × 10⁻¹⁶
Answer: 10 grams of Hydrogen gas will be produced theoretically.
Explanation: The equation for the reaction between zinc metal and hydrochloric acid is:
As HCl is present in excess, therefore limiting reagent is Zinc metal as it limits the formation of product.
By stoichiometry,
1 mole of Zinc metal produces 1 mole of Hydrogen gas, therefore
Amount of Hydrogen gas produced can be calculated by:
Molar mass of Hydrogen = 2 g/mol
Mass of hydrogen gas produced = (5 moles )× (2 g/mol)
Mass of hydrogen gas produced = 10 grams