Physical Chemistry 1: Amount of substance multiple choice questions

1. How many molecules are in 15.0 g of PH3?
(Avogadro’s number is 6.022 x 1023)

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2. What is the molar mass of an oxygen atom?

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3. The density of pure water is 1000 g dm-3.
What is the molarity of pure water?

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4. Calculate the mass of KOH that should be dissolved in 500 cm3 water to give a solution with a concentration of 0.600 mol dm-3

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5. A 1 dm3 sample of Noble gas X contains 0.04471 moles. The density of the gas is 1.784 g dm-3.
Which gas does the sample contain?

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6. Calculate the concentration of the solution that is formed by adding 50 cm3 of water to 25 cm3 of 0.268 mol dm-3 HCl

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7. 0.05 moles of an Iron salt FeClx reacts with AgNO3to form 21.5 g of AgCl. What is the value of x?

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8. A The uncertainty of a balance is + 0.1g.
What is the % uncertainty if this balance is used to measure 26.7 g of CuSO4?

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9. What is the formula of Iron(II) Carbonate?

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10. Dinitrogen Monoxide decomposes to produce Nitrogen and Oxygen according to the following equation:

2N2O(g) → 2N2(g) + O2(g)

Assuming a constant temperature, how many times greater is the volume of the products than the volume of the reactants?

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