What mass of MgSO4 · 7H2O is required to prepare 800 mL of a 0.442MMgSO4 solution?

Answer in units of g.

Would you use the formula M1V1=M2V2?

What is the molar mass?

Yes, you can use the formula M1V1 = M2V2 to solve this problem. The formula relates the initial concentration (M1) and volume (V1) to the final concentration (M2) and volume (V2) after dilution.

First, let's rearrange the formula to solve for M1, which represents the initial concentration:

M1 = (M2V2) / V1

Now, let's plug in the values given in the problem:

M2 = 0.442 M (final concentration)
V2 = 800 mL (final volume)
V1 = unknown (initial volume, but we don't need it for this calculation)

M1 = (0.442 M * 800 mL) / V1

Since we don't have the initial volume, we need an additional piece of information before we can proceed.

Yes, to solve this problem, you can use the formula M1V1 = M2V2, also known as the dilution formula. Let's go step by step to find the mass of MgSO4 · 7H2O required to prepare the solution.

First, let's understand the given information:
- Final volume (V2) = 800 mL (or 0.8 L)
- Final concentration (M2) = 0.442 M

Now, we need to find the initial molar concentration (M1) and the mass of MgSO4 · 7H2O required.

To calculate the initial molar concentration (M1) we need the molar mass of MgSO4 · 7H2O.
- The molar mass of MgSO4 = 24.31 g/mol (Mg) + 32.07 g/mol (S) + (4 × 16.00 g/mol) (O) = 120.37 g/mol
- The molar mass of H2O = 2 × (1.01 g/mol) (H) + 16.00 g/mol (O) = 18.02 g/mol

The molar mass of MgSO4 · 7H2O can be calculated by adding the molar masses of MgSO4 and 7H2O together:
- Molar mass of MgSO4 · 7H2O = 120.37 g/mol + (7 × 18.02 g/mol) = 246.47 g/mol

Now, let's use the dilution formula to find M1:
M1V1 = M2V2
M1 = (M2V2) / V1

Plug in the values we know:
M2 = 0.442 M
V2 = 0.8 L
V1 = the initial volume (which is unknown)

To find V1, we rearrange the equation:
V1 = (M2V2) / M1

Substituting the values:
V1 = (0.442 M) × (0.8 L) / M1

Since we don't know the exact volume required to dissolve the MgSO4 · 7H2O, V1 will remain as a variable.

Now, to find the mass of MgSO4 · 7H2O, we can use the formula:
Mass = Molar mass × Moles

To find the moles, we use the formula:
Moles = Molarity × Volume

Substituting the values:
Moles = M1 × V1

Now, the equation becomes:
Mass = Molar mass × (M1 × V1)

We can substitute V1 from the previous equation into the mass equation, which gives us:
Mass = Molar mass × (M1 × ((0.442 M) × (0.8 L) / M1))

Simplify the equation:
Mass = Molar mass × (0.442 M) × (0.8 L)

Now, plug in the known values:
Mass = (246.47 g/mol) × (0.442 M) × (0.8 L)

Calculating the mass using the equation above will give you the answer in units of grams.

No, that formula is no good for calculating mass.

I would go about it this way.
moles needed = M x L = 0.442 x 0.800 = ??
Then moles = grams/molar mass. You know moles from the first calculation and you know molar mass, solve for grams.