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Grade 9 · Chemistry

Grade 9 Chemistry diagnostic

16 questions on general chemistry, chemical reactions, acids, bases & ph, inorganic chemistry, analytical chemistry, physical chemistry and organic chemistry, plus 2 from Grade 8. Answer what you can, then check your answers to see which topics are secure and what to practise next.

16 questions7 topicsAbout 20 minutesSet 2 of 5

Skip a question if you do not know the answer. It is better than guessing, because it shows what to practise.

1General chemistryA model sample has mass 95 g and stated molar mass 46 g/mol. Find its amount. Round to 3 decimal places if needed. Answer in mol.
mol
2General chemistryWhich is the correct formula for the ionic compound formed from sodium (Na) and fluorine (F)?
3Chemical reactionsBalance this equation using the smallest whole-number coefficients: __ C₄H₁₀ + __ O₂ → __ CO₂ + __ H₂O. What is the coefficient of C₄H₁₀?
4Chemical reactionsIn a sealed container, 29.3 g of A and 19.5 g of B react until B is used up. 26.4 g of A is left over, and the only product is C. What mass of C forms?
g
5Acids, bases & pHHow many times greater is the hydrogen-ion concentration in a solution of pH 3 than in a solution of pH 4?
6Acids, bases & pHA solution at 25 °C has a pH of 2.5. Is it acidic, neutral or basic?
7Inorganic chemistryAn atom gains one electron while retaining 9 protons. How many electrons does the resulting ion have if the atom was neutral?
8Inorganic chemistryIn neutral MgO, oxygen is assigned −2. What is magnesium’s oxidation state?
9Analytical chemistryThe theoretical dry pure product mass is 61 g; the actual dry pure product mass is 5 g. Find percentage yield. Round to 3 decimal places if needed. Answer in %.
%
10Analytical chemistryA 25 mL aliquot at 1.6 mol/L is diluted to 300 mL total without reaction or loss. Find the final concentration. Round to 3 decimal places if needed. Answer in mol/L.
mol/L
11Physical chemistryA reactant concentration falls from 0.80 to 0.50 mol/L in 30 s. What is its average disappearance rate?
mol/(L·s)
12Physical chemistryWhich sign normally describes ΔH for an exothermic reaction?
13Organic chemistryWhich is conventionally treated as an inorganic carbon compound?
14Organic chemistryWhich feature generally restricts chains from sliding past one another?

From Grade 8

These questions check skills from the grade below, so gaps can be spotted early.

15General chemistry (Grade 8)Which is a mixture?
16General chemistry (Grade 8)A stated mixture has 12 g of one component and 8 g of another. What is its total mass?
g