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🧪 Chemistry, NCEA

Years 11 to 13 · Read up first

10 questions. Get 8 right to earn 10 minutes. All 10 right = +5 bonus. They start easy and get harder as you go, so treat the first few as a warm-up. Every one you miss comes back with the answer and why.

1. Which of these generally increases the rate of a chemical reaction?

Using a smaller volume of the same concentration solution aloneDecreasing the temperatureRemoving the reactantsIncreasing the temperature

2. The pH scale runs from

0 to 140 to 100-7 to 71 to 10

3. Using a catalyst in a reaction

speeds up the reaction without being used up itselfslows the reaction downis permanently changed into a new substanceonly works at very low temperatures

4. Elements in the periodic table are arranged in order of increasing

atomic number (number of protons)alphabetical orderatomic mass onlynumber of neutrons

5. Concentration in mol/L (molarity) is calculated using

moles of solute divided by volume of solution in litresmass of solute divided by mass of solventmoles of solute multiplied by volume in litresvolume of solution divided by moles of solute

6. How many moles of solute are in 0.5 litres of a 2 mol/L solution?

2.5 mol1 mol4 mol0.25 mol

7. Reduction is best defined (in terms of electrons) as

loss of neutronsgain of electronsloss of electronsgain of protons

8. As pH decreases from 7 towards 0, a solution becomes

More alkalineMore acidicLess concentratedMore neutral

9. Ammonia (NH3) has three bonding pairs and one lone pair around its central nitrogen atom. What shape does this give the molecule?

Trigonal pyramidalTetrahedralLinearTrigonal planar

10. Using the equation N2 + 3H2 -> 2NH3, what mass of ammonia (NH3, molar mass 17 g/mol) can be produced from 6 moles of hydrogen gas?

68 g17 g102 g34 g

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