Stoichiometry

Find the relative formula mass of silver nitrate ($AgNO_3$). (Given $A_r$: $Ag=108, N=14, O=16$)

Calculate the $M_r$ of sodium oxide ($Na_2O$). (Given $A_r$: $Na=23, O=16$)

What is the $M_r$ of potassium bromide ($KBr$)? (Given $A_r$: $K=39, Br=80$)

Calculate the $M_r$ of helium gas ($He$). (Given $A_r$: $He=4$)

Aluminium chloride often exists as a dimer, $Al_2Cl_6$. What is the relative molecular mass of this dimer? (Given $A_r$: $Al=27, Cl=35.5$)

Calculate the relative formula mass of sodium bicarbonate, $NaHCO_3$. (Given $A_r$: $Na=23, H=1, C=12, O=16$)

What is the relative formula mass of barium sulfate, $BaSO_4$? (Given $A_r$: $Ba=137, S=32, O=16$)

A substance contains $1.204 \times 10^{24}$ molecules of a gas $X$. If the mass of this sample is 64 g, what is the $M_r$ of $X$?

An unknown gas $G$ has a mass of 0.80 g and occupies a volume of $600 cm^3$ at r.t.p. What is its $M_r$?

A compound contains 40% Carbon, 6.7% Hydrogen and 53.3% Oxygen. Its $M_r$ is 60. What is its molecular formula? (Given $A_r$: $C=12, H=1, O=16$)

What is the empirical formula of phosphorus(V) oxide, $P_4O_{10}$?

If a sample of helium gas ($He$) occupies 2.4 $dm^3$ at r.t.p., what is its mass? ($He=4$)

What is the $M_r$ of sugar (glucose), $C_6H_{12}O_6$? ($C=12, H=1, O=16$)

How many atoms are in 0.5 moles of zinc ($Zn$)? (Let $L$ be the Avogadro constant)

What volume of $0.5\ mol/dm^3$ $H_2SO_4$ is needed to react with 4.0g of $NaOH$? ($M_r: NaOH = 40$; Ratio 1:2)

Which of the following contains the same number of atoms as 12g of Carbon-12?

What is the number of moles of gas present in a container of $600\ cm^3$ at r.t.p.?

When $1.0$ mole of an element $E$ reacts with excess oxygen, $94$ g of an oxide $E_2O$ is formed. What is the relative atomic mass of $E$? ($A_r: O=16$)

A $5.85$ g sample of $NaCl$ is dissolved in water to make $250$ $cm^3$ of solution. What volume of this solution contains $0.01$ moles of $NaCl$? ($M_r$ of $NaCl = 58.5$)

What is the percentage by mass of nitrogen in urea, $CO(NH_2)_2$? ($A_r: C=12, O=16, N=14, H=1$)

A sample contains 0.1 moles of Iron and 0.15 moles of Oxygen. What is the empirical formula of the oxide?

What is the empirical formula of cyclohexane ($C_6H_{12}$)?

If the empirical formula of a compound is $CH$, which of the following is NOT a possible molecular formula?

What is the empirical formula of a compound containing 40% Calcium, 12% Carbon, and 48% Oxygen by mass? ($Ca=40, C=12, O=16$)

An oxide of manganese contains 63.2% manganese by mass. What is its empirical formula? ($A_r: Mn=55, O=16$)

A compound contains 78.2% boron and 21.8% hydrogen by mass. What is its empirical formula? ($A_r: B=10.8, H=1$)

Titanium reacts with chlorine to form a chloride. If 1.20 g of titanium reacts with 3.55 g of chlorine, what is the empirical formula? ($A_r: Ti=48, Cl=35.5$)

A compound contains $75\%$ carbon and $25\%$ hydrogen by mass. What is its empirical formula? ($A_r: C=12, H=1$)

A compound of phosphorus and chlorine contains $22.5\%$ phosphorus. What is its empirical formula? ($A_r: P=31, Cl=35.5$)

An organic compound $X$ has an empirical formula $CH_2$. $0.5 \text{ moles}$ of $X$ contains $4.0 \text{ g}$ of hydrogen. What is the molecular formula of $X$?

What is the relative atomic mass ($A_r$) of Carbon?

Convert $2.5\ dm^3$ to $cm^3$.

What is the $M_r$ of calcium oxide, $CaO$? ($A_r: Ca=40, O=16$)

What is the mass of $3\ moles$ of $O_2$? ($M_r = 32$)

What mass of phosphorus(III) chloride is formed from $6.2\ g$ of phosphorus reacting with excess chlorine? $2P + 3Cl_2 \rightarrow 2PCl_3$ (Relative atomic masses: $P=31, Cl=35.5$)

What mass of silver nitrate ($AgNO_3$) is required to produce $17\ g$ of silver by displacement with copper? $Cu + 2AgNO_3 \rightarrow Cu(NO_3)_2 + 2Ag$ ($M_r$ of $AgNO_3 = 170$; Relative atomic mass $Ag=108$)

A hydrocarbon contains $80\%$ carbon and $20\%$ hydrogen by mass. What is its empirical formula? (Relative atomic masses: $C=12, H=1$)

If $48\ g$ of magnesium is reacted with $48\ g$ of oxygen to form magnesium oxide, what is the mass of the reactant in excess? ($A_r: Mg=24, O=16$)

$10\ cm^3$ of ethane ($C_2H_6$) is mixed with $60\ cm^3$ of oxygen and ignited. What is the total volume of gas remaining at RTP? $2C_2H_6 + 7O_2 \rightarrow 4CO_2 + 6H_2O$

A metal $X$ forms an oxide $X_2O_3$. If $0.1\ mol$ of $X$ weighs $2.7\ g$, what is the mass of $0.1\ mol$ of its oxide?

When recording titration data, what are 'concordant' titres?

How many moles are in $100\ cm^3$ of a $2.0\ mol/dm^3$ solution?

The molar mass of $HCl$ is $36.5\ g/mol$. What is the concentration in $g/dm^3$ of a $1.0\ mol/dm^3$ $HCl$ solution?

Calculate the moles of $HCl$ in $50\ cm^3$ of $0.5\ mol/dm^3$ solution.

How many water molecules are associated with one formula unit of $MgSO_4 \cdot xH_2O$ if $2.46\ g$ of the hydrated salt is dissolved to make $100\ cm^3$ of a $0.1\ mol/dm^3$ solution? ($M_r$ of $MgSO_4 = 120$)

A student uses $0.1\ mol/dm^3$ $NaOH$ to titrate $25.0\ cm^3$ of an unknown acid. If the volume of $NaOH$ needed is $50.0\ cm^3$, and the acid-to-base ratio is 1:2, what is the acid concentration?

What is the concentration of $250\ cm^3$ of a solution containing $0.025\ moles$ of solute?

What is the molar concentration of a $10.0\%$ by mass solution of $NaCl$ with a density of $1.07\ g/cm^3$?

A sample of gas-works liquor contains ammonia. $25.0\ cm^3$ of the liquor was boiled with $50.0\ cm^3$ of $0.500\ mol/dm^3$ $NaOH$. The remaining $NaOH$ required $15.0\ cm^3$ of $0.250\ mol/dm^3$ $H_2SO_4$. What was the concentration of ammonia in the liquor?

What mass of $K_2Cr_2O_7$ is required to prepare $500\ cm^3$ of a $0.0200\ mol/dm^3$ solution? ($M_r = 294.2$)