145k views
3 votes
Write your question here (Keep it simple and clear to get the best answer) calculate the atomic weight of a metal when 125ml of of a 0.2 M HCl reacts with 0.304g of the metal using the eqn M +2HCL-------MCL2+H2

User Tobbs
by
5.6k points

2 Answers

7 votes

Answer:

The molar mass of the metal is 24.32 g/mol (Magnesium)

Step-by-step explanation:

Step 1: Data given

volume of a 0.2 M HCl = 125 mL = 0.125 L

Mass of the metal = 0.304 grams

Step 2: The balanced equation

M + 2HCL ⇔ MCL2+ H2

Step 3: Calculate moles of HCl

Moles HCl = molarity * volume

Moles HCl = 0.2 M * 0.125 L

Moles HCl = 0.025 moles

Step 4: Calculate moles M

For 1 mol M we need 2 moles HCl to produce 1 mol MCl2 and 1 mol H2

For 0.025 moles HCl we have 0.025/2 = 0.0125 moles M

Step 5: Calculate molar mass M

Molar mass M = mass M / moles M

Molar mass M = 0.304 grams / 0.0125 moles

Molar mass M = 24.32 g/mol

The molar mass of the metal is 24.32 g/mol (Magnesium)

User Yago Azedias
by
5.7k points
5 votes

Answer:

The answer to your question is 24.32 g

Step-by-step explanation:

Data

Atomic weight = ?

HCl volume = 125 ml

Molarity = 0.2

mass of metal = 0.304 g

Balanced chemical equation

M + 2HCl ⇒ MCl₂ + H₂

Process

1.- Calculate the moles of HCl

Molarity = moles / volume (L)

- Solve for moles

moles = Molarity x volume

moles = 0.2 x 0.125

= 0.025

2.- Calculate the moles of the Metal

1 mol of M ----------------- 2 moles of HCl

x ----------------- 0.025 moles of HCl

x = (0.025 x 1) / 2

x = 0.0125 moles of HCl

3.- Calculate the atomic weight of the metal

atomic weight ---------------- 1 mol

0.304 g ---------------0.0125 moles

Atomic weight = (1 x 0.304) / 0.0125

Atomic weight = 24.32 g

User Kealist
by
5.8k points