Question

1. How many kmols are in 890 cg of sodium phosphate?
2. How many pg are in 365 amol of potassium perchlorate?
3. How many damol are in 1000 dg of arsenic ( III ) sulfide?
4. How many hg are in 740.00 fg of barium hydroxide?

Answer 1

Answer on Question#72579 – Chemistry – Organic chemistry

Question:

1. How many kmols are in 890 cg of sodium phosphate?

Solution:

1 cg = 0.01g

890cg = 8.90 g

$$M(\mathrm{Na_3PO_4}) = 163.9 \text{ g/mol}$$ $$n(\mathrm{Na_3PO_4}) = \frac{m(\mathrm{Na_3PO_4})}{M(\mathrm{Na_3PO_4})} = \frac{8.90 \text{ g}}{163.9 \frac{\text{g}}{\text{mol}}} = 0.0543 \text{ mol}$$

1 mol = $10^{-3}$ kmol

0.0543 mol = $5.43 \times 10^{-5}$ kmol

Answer:

$5.43 \times 10^{-5}$ kmol $\mathrm{Na_3PO_4}$

Question:

2. How many pg are in 365 amol of potassium perchlorate?

Solution:

1 amol = $10^{-18}$ mol

365 amol = $3.65 \times 10^{-16}$ mol

$$M(\mathrm{KClO_4}) = 138.6 \text{ g/mol}$$ $$m(\mathrm{KClO_4}) = n(\mathrm{KClO_4}) \times M(\mathrm{KClO_4}) = 3.65 \times 10^{-16} \text{ mol} \times 138.6 \frac{\text{g}}{\text{mol}} = 5.06 \times 10^{-14} \text{ g}$$

1g = $10^{12}$ pg

$5.06 \times 10^{-14}$ g = 0.0506 pg.

Answer:

0.0506 pg $\mathrm{KClO_4}$

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Question:

3. How many damol are in 1000 dg of arsenic (III) sulfide?

Solution:

1 dg = 0.1 g

1000 dg = 100 g

$\mathrm{M}(\mathrm{As}_2\mathrm{S}_3) = 246.0\mathrm{g / mol}$

$$\mathrm{n}(\mathrm{As}_2\mathrm{S}_3) = \frac{\mathrm{M}(\mathrm{As}_2\mathrm{S}_3)}{\mathrm{M}(\mathrm{As}_2\mathrm{S}_3)} = \frac{100\mathrm{g}}{246.0\mathrm{g / mol}} = 0.407\mathrm{mol}$$

1 mol = 0.1 damol

0.407 mol = 0.0407 damol

Answer:

0.0407 damol $\mathrm{As}_2\mathrm{S}_3$

Question:

4. How many hg are in 740.00 fg of barium hydroxide?

Solution:

1 fg = $10^{-15}$ g

1 hg = $10^{2}$ g

$$740.00 \text{ fg} \times \frac{10^{-15} \text{ g}}{1 \text{ fg}} \times \frac{1 \text{ hg}}{10^{2} \text{ g}} = 7.4000 \times 10^{-15} \text{ hg}$$

Answer:

$7.4000 \times 10^{-15} \text{ hg Ba(OH)}_2$