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CHEMISTRY, M1 EQ-Bank 9 MC

The formula for the sulfate ion is \(\ce{SO4^2-}\). What is the formula for aluminium sulfate?

  1. \(\ce{AlSO4}\)
  2. \(\ce{Al2SO4}\)
  3. \(\ce{Al(SO4)3}\)
  4. \(\ce{Al2(SO4)3}\)
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\(D\)

Show Worked Solution
  • Aluminum has a charge of \(3+\) and sulfate has a charge of \(2-\). To form a neutral compound, the charges must balance.
  • Using the criss-cross method, we need 2 aluminum ions (total charge: \(2 \times 3 = 6+\)) and 3 sulfate ions (total charge: \(3 \times 2- = 6-\)) to achieve a neutral compound.
  • Therefore, the formula is \(\ce{Al2(SO4)3}\).

\(\Rightarrow D\)

CHEMISTRY, M1 EQ-Bank 6 MC

Elements \(\ce{A}\) and \(\ce{B}\) are in the same period of the Periodic Table. Element \(\ce{A}\) has 1 electron in its outer shell, and element \(\ce{B}\) has 6 electrons in its outer shell.

What is the likely formula of the compound they form together?

  1. \(\ce{A2B}\)
  2. \(\ce{AB2}\)
  3. \(\ce{A2B6}\)
  4. \(\ce{A6B2}\)
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\(A\)

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  • \(\ce{A}\) (1 valence electron) → Group 1 → forms \(\ce{A^+}\).
  • \(\ce{B}\) (6 valence electrons) → Group 16 → forms \(\ce{B^2-}\) ions.
  • Hence they will form the compound with the formula \(\ce{A2B}\).

\(\Rightarrow A\)

CHEMISTRY, M1 EQ-Bank 4 MC

The formula for sodium thiosulfate is \(\ce{Na2S2O3}\).

What is the formula for aluminium thiosulfate?

  1. \(\ce{AlS2O3}\)
  2. \(\ce{Al2(S2O3)3}\)
  3. \(\ce{Al3S2O3}\)
  4. \(\ce{Al(S2O3)2}\)
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\(B\)

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  • From the sodium thiosulfate ion we can identify that it contains a sodium ion \(\ce{Na^+}\) and the thiosulfate ion \(\ce{S2O3^2-}\).
  • The aluminium ion is \(\ce{Al^3+}\).
  • Hence the correct formula for aluminium thiosulfate ion is \(\ce{Al2(S2O3)3}\).

\(\Rightarrow B\)

CHEMISTRY, M1 EQ-Bank 3 MC

What is the correct systematic (IUPAC) name for \(\ce{Ca(NO3)2}\)?

  1. Calcium dinitrogen trioxide
  2. Calcium dinitrate
  3. Calcium nitrate
  4. Calcium\(\text{(I)}\) dinitrate
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\(C\)

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  • For all ionic compounds, the names is written with the metal/postive ion and non-metal/negative ion.
  • The metal (cation) is written first with the name unchanged.
  • The non-metal (anion) is written second and the name is modified to end in either -ide, -ate, or -ite. For this compound, the name of the polyatomic ion is nitrate.

\(\Rightarrow C\)

CHEMISTRY, M1 EQ-Bank 2 MC

Which of the following lists contains only metals?

  1. Calcium, copper, zinc, potassium
  2. Magnesium, aluminium, silicon, iron
  3. Sodium, tin, iodine, lead
  4. Lithium, carbon, nickel, bromine
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\(A\)

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  • In the incorrect answers silicon is a metalloid while iodine, carbon and bromine are all non-metals.

\(\Rightarrow A\)

CHEMISTRY, M1 EQ-Bank 1 MC

What is the formula of magnesium nitride?

  1. \(\ce{MgN}\)
  2. \(\ce{Mg2N3}\)
  3. \(\ce{Mg3N2}\)
  4. \(\ce{MgN2}\)
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\(C\)

Show Worked Solution
  • The mageniusm forms a \(\ce{Mg^2+}\) ion and nitrogen forms a \(\ce{N^3-}\). 
  • Using the swap and drop method, the \(2\) from the magnesium becomes the subscript for the nitrogen and vise versa.
  • Hence the correct formula is \(\ce{Mg3N2}\).

\(\Rightarrow C\)

CHEMISTRY, M1 EQ-Bank 8

Name the following inorganic compounds:

  1. \(\ce{HClO}\)   (1 mark)
  2. \(\ce{NaHCO3}\)   (1 mark)
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  1. Hypochlorous Acid
  2. Sodium Bicarbonate
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a.    Hypochlorous Acid

b.   Sodium Bicarbonate