We read your photo as:

How many moles of zinc are there in 2.08 g of anhydrous zinc sulphate? How many moles of water were lost?

Chemistry

ScanSolve AI Answer

Answers

3 parts
b(i)

0.0129 mol\text{0.0129 mol}

b(ii)

0.0908 mol\text{0.0908 mol}

b(iii)
7

Step-by-step solution

8 steps

Part b(i)· 3 steps

How many moles of zinc are there in 2.08 g2.08 \text{ g} of anhydrous zinc Sulphate?

  1. Calculate the molar mass of anhydrous zinc sulfate (ZnSO4\text{ZnSO}_4).

    Given atomic masses: Zn=65\text{Zn} = 65, S=32\text{S} = 32, O=16\text{O} = 16.

    Molar mass of ZnSO4=Zn+S+(4×O)\text{Molar mass of ZnSO}_4 = \text{Zn} + \text{S} + (4 \times \text{O}) Molar mass of ZnSO4=65+32+(4×16)=65+32+64=161 g/mol\text{Molar mass of ZnSO}_4 = 65 + 32 + (4 \times 16) = 65 + 32 + 64 = 161 \text{ g/mol}

  2. Calculate the moles of anhydrous zinc sulfate.

    Moles of ZnSO4=Mass of ZnSO4Molar mass of ZnSO4\text{Moles of ZnSO}_4 = \frac{\text{Mass of ZnSO}_4}{\text{Molar mass of ZnSO}_4} Moles of ZnSO4=2.08 g161 g/mol≈0.012919 mol\text{Moles of ZnSO}_4 = \frac{2.08 \text{ g}}{161 \text{ g/mol}} \approx 0.012919 \text{ mol}

  3. Determine the moles of zinc.

    From the formula ZnSO4\text{ZnSO}_4, 1 mole of ZnSO4\text{ZnSO}_4 contains 1 mole of Zn\text{Zn}.

    Moles of Zn=Moles of ZnSO4\text{Moles of Zn} = \text{Moles of ZnSO}_4 Moles of Zn≈0.0129 mol\text{Moles of Zn} \approx 0.0129 \text{ mol}

    There are approximately 0.0129 mol\boxed{\text{0.0129 mol}} of zinc in 2.08 g2.08 \text{ g} of anhydrous zinc sulfate.

Part b(ii)

0.0908 mol\text{0.0908 mol}

How many moles of water were lost?

  1. Calculate the mass of water lost.

    Initial mass of hydrated crystals = 3.715 g3.715 \text{ g}
    Mass of anhydrous zinc sulfate = 2.08 g2.08 \text{ g}

    Mass of water lost=Initial mass−Mass of anhydrous salt\text{Mass of water lost} = \text{Initial mass} - \text{Mass of anhydrous salt} Mass of water lost=3.715 g−2.08 g=1.635 g\text{Mass of water lost} = 3.715 \text{ g} - 2.08 \text{ g} = 1.635 \text{ g}

  2. Calculate the molar mass of water (H2O\text{H}_2\text{O}).

    Given atomic masses: H=1\text{H} = 1, O=16\text{O} = 16.

    Molar mass of H2O=(2×H)+O\text{Molar mass of H}_2\text{O} = (2 \times \text{H}) + \text{O} Molar mass of H2O=(2×1)+16=2+16=18 g/mol\text{Molar mass of H}_2\text{O} = (2 \times 1) + 16 = 2 + 16 = 18 \text{ g/mol}

  3. Calculate the moles of water lost.

    Moles of H2O=Mass of H2OMolar mass of H2O\text{Moles of H}_2\text{O} = \frac{\text{Mass of H}_2\text{O}}{\text{Molar mass of H}_2\text{O}} Moles of H2O=1.635 g18 g/mol≈0.090833 mol\text{Moles of H}_2\text{O} = \frac{1.635 \text{ g}}{18 \text{ g/mol}} \approx 0.090833 \text{ mol}

    Approximately 0.0908 mol\boxed{\text{0.0908 mol}} of water were lost.

Part b(iii)7

Determine the value of nn in the formula ZnSO4⋅nH2O\text{ZnSO}_4 \cdot n\text{H}_2\text{O}.

  1. Use the moles of anhydrous zinc sulfate and moles of water lost.

    From part (i), Moles of ZnSO4≈0.012919 mol\text{ZnSO}_4 \approx 0.012919 \text{ mol}.
    From part (ii), Moles of H2O≈0.090833 mol\text{H}_2\text{O} \approx 0.090833 \text{ mol}.

  2. Calculate the ratio of moles of water to moles of zinc sulfate to find nn.

    n=Moles of H2OMoles of ZnSO4n = \frac{\text{Moles of H}_2\text{O}}{\text{Moles of ZnSO}_4} n=0.090833 mol0.012919 mol≈7.03n = \frac{0.090833 \text{ mol}}{0.012919 \text{ mol}} \approx 7.03

    Rounding to the nearest whole number, n=7n = 7.
    The value of nn is 7\boxed{7}.

Was this helpful?

Try one yourself

A new problem that tests the same skill.

Still stuck on this one?

Ask a follow-up, and the answer starts from this question.

Got a different question?Ask your own question

More Chemistry Questions

Qb) 7.50g of a hydrated copper(II) sulphate (CuSO4.nH2O) on heating gave 4.8g of anhydrous copper(II)…QCalculate the amount of hydrogen gas produced when 1.96 g of zinc reacts with 100 cm3 of 0.2 M HCl.QWhen 6.5g of Zinc powder are added to 250cm of 0.1M copper 2 sulphate solution in a plastic…QWhat mass of zinc sulfate crystals (ZnSO4·7H2O) is needed to provide 15 mg of zinc?QWhat mass of zinc will be required to react completely with 100 cm3 of 0.1 moldm⁻³ hydrochloric…
See all Chemistry questions →
Got a syllabus? Photograph it and I'll tell you what's due and what's worth the most.
Handwritten step-by-step solution preview

Handwritten Step-by-Step Solution

Get this as a handwritten image on WhatsApp — like a tutor wrote it for you.

Try on WhatsApp