Atoms, Molecules and Stoichiometry

Complete the table.

Define the term relative isotopic mass.

Calculate the relative isotopic mass of $^{11}\text{B}$.

Give your answer to six significant figures. Show your working.

Calculate the amount, in moles, of hydrochloric acid used in the titration to neutralise the unreacted sodium hydroxide solution.

Write the equation for the reaction between hydrochloric acid and sodium hydroxide.

Calculate the amount, in moles, of sodium hydroxide neutralised in the titration.

Calculate the amount, in moles, of sodium hydroxide that reacted with the $\text{HCl}$ produced by the reaction in equation 1.

Calculate the amount, in moles, of $\text{HCl}$ produced by the reaction in equation 1.

Calculate the amount, in moles, of $\text{XCl}_4$ in the original $0.17\text{ g}$ sample.

Calculate the molecular mass, $M_{\text{r}}$, of $\text{XCl}_4$.

Calculate the relative atomic mass, $A_{\text{r}}$, of $\text{X}$ and suggest its identity.

Calculate the amount, in moles, of hydrochloric acid present in $40.0\text{ cm}^3$ of $1.00\text{ mol dm}^{-3}$ $\text{HCl}$.

Write the equation for the complete reaction of sodium carbonate with hydrochloric acid.

Calculate the amount, in moles, of sodium carbonate needed to react with the hydrochloric acid in the $10.0\text{ cm}^3$ sample from the volumetric flask.

Calculate the amount, in moles, of hydrochloric acid in the $10.0\text{ cm}^3$ sample.

Calculate the total amount, in moles, of hydrochloric acid remaining after the reaction shown in equation 1.

Use your answers to (a) and (b)(iv) to calculate the amount, in moles, of hydrochloric acid that reacted with the $0.50\text{ g}$ sample of M.

Use your answer to (v) and equation 1 to calculate the amount, in moles, of M in the $0.50\text{ g}$ sample.

Calculate the relative atomic mass, $A_r$, of M and identify M.

Calculate the amount, in moles, of hydrochloric acid used in the titration to neutralise the unreacted sodium hydroxide solution.

Write the equation for the reaction between hydrochloric acid and sodium hydroxide.

Calculate the amount, in moles, of sodium hydroxide neutralised in the titration.

Calculate the amount, in moles, of sodium hydroxide that reacted with the $\text{HCl}$ produced by the reaction in equation 1.

Calculate the amount, in moles, of $\text{HCl}$ produced by the reaction in equation 1.

Calculate the amount, in moles, of $\text{XCl}_4$ in the original $0.17\text{ g}$ sample.

Calculate the molecular mass, $M_r$, of $\text{XCl}_4$.

Calculate the relative atomic mass, $A_r$, of $\text{X}$ and suggest its identity.

Ammonium sulfate reacts with $\text{NaOH}$ in a $1:2$ ratio.

Complete and balance the equation for this reaction.

Write a balanced equation for the reaction between $\text{NaOH}$ and $\text{HCl}$.

Calculate the amount, in moles, of $\text{HCl}$ in $31.2\text{ cm}^3$ of $1.00\text{ mol dm}^{-3}$ $\text{HCl}$.

Calculate the amount, in moles, of $\text{NaOH}$ in $50.0\text{ cm}^3$ of $2.00\text{ mol dm}^{-3}$ $\text{NaOH}$.

Use your answers to (i), (ii) and (iii) to calculate the amount, in moles, of $\text{NaOH}$ used up in the reaction with $(\text{NH}_4)_2\text{SO}_4$.

Use your answer to (iv) and the equation in (a) to calculate the amount, in moles, of $(\text{NH}_4)_2\text{SO}_4$ that reacted with $\text{NaOH}$.

Use your answer to (v) to calculate the mass of $(\text{NH}_4)_2\text{SO}_4$ that reacted with $\text{NaOH}$.

Hence, calculate the percentage purity of the ammonium sulfate fertiliser.

Write a balanced equation for the reaction between Na₂CO₃ and HCl.

Calculate the amount, in moles, of HCl in the 35.8 cm³ of solution used in the titration.

Use your answers to (i) and (ii) to calculate the amount, in moles, of Na₂CO₃ in the 25.0 cm³ of solution used in the titration.

Use your answer to (iii) to calculate the amount, in moles, of Na₂CO₃ in the 250 cm³ of solution in the standard volumetric flask.

Hence calculate the mass of Na₂CO₃ present in 5.13 g of washing soda crystals.

Use your calculations in (a) to determine the value of x in Na₂CO₃.xH₂O.

One salt which is used as a dietary supplement is a hydrated zinc sulfate, $\text{ZnSO}_4\cdot x\text{H}_2\text{O}$, which is a colourless crystalline solid.

Crystals of zinc sulfate may be prepared in a school or college laboratory by reacting dilute sulfuric acid with a suitable compound of zinc.

Give the formulae of two simple compounds of zinc that could each react with dilute sulfuric acid to produce zinc sulfate.

Why was the boiling tube heated, cooled and reweighed four times?

Calculate the amount, in moles, of the anhydrous salt produced.

Calculate the amount, in moles, of water driven off by heating.

Use your results to (ii) and (iii) to calculate the value of $x$ in $\text{ZnSO}_4\cdot x\text{H}_2\text{O}$.

What mass of pure crystalline zinc ethanoate ($M_r = 219.4$) will need to be taken to obtain a dose of $15\text{ mg}$ of zinc?

If this dose is taken in solution as $5\text{ cm}^3$ of aqueous zinc ethanoate, what would be the concentration of the solution used?

Give your answer in $\text{mol dm}^{-3}$.

One salt which is used as a dietary supplement is a hydrated zinc sulfate, $\text{ZnSO}_4 \cdot x\text{H}_2\text{O}$, which is a colourless crystalline solid.

Crystals of zinc sulfate may be prepared in a school or college laboratory by reacting dilute sulfuric acid with a suitable compound of zinc.

Give the formulae of two simple compounds of zinc that could each react with dilute sulfuric acid to produce zinc sulfate.

Why was the boiling tube heated, cooled and reweighed four times?

Calculate the amount, in moles, of the anhydrous salt produced.

Calculate the amount, in moles, of water driven off by heating.

Use your results to (ii) and (iii) to calculate the value of $x$ in $\text{ZnSO}_4 \cdot x\text{H}_2\text{O}$.

What mass of pure crystalline zinc ethanoate ($M_r = 219.4$) will need to be taken to obtain a dose of $15\text{ mg}$ of zinc?

If this dose is taken in solution as $5\text{ cm}^3$ of aqueous zinc ethanoate, what would be the concentration of the solution used?

Give your answer in $\text{mol dm}^{-3}$.

When calcium carbide is reacted with water, ethyne and calcium hydroxide are formed.

Construct a balanced equation for this reaction.

Write balanced equations, with state symbols, that represent

the standard enthalpy change of combustion, $\Delta H_c^\ominus$, of C₂H₂, and

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the standard enthalpy change of formation, $\Delta H_f^\ominus$, of C₂H₂.

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