Chapter 4 Grade 10 SABIS chemistry Quiz Level L Part 1

Which of the following is a physical change? Which is a chemical change? 1. Heating wax until it melts [blank_start]Physical[blank_end] 2. Crush some salt crystals into a powder [blank_start]Physical[blank_end] 3. Boiling water until it evaporates, then condensing the steam. [blank_start]Physical[blank_end] 4. Boiling an egg in boiling water for two minutes, then cooling the water. [blank_start]Physical[blank_end] 5. Heating a piece of paper until it turns black, then cooling it. [blank_start]Physical[blank_end] 6. Heating a mixture of hydrogen and oxygen until it “pops”, and then cooling the gases to a liquid. [blank_start]Physical[blank_end] 7. Dissolving salt into water to make a solution [blank_start]Physical[blank_end] 8. Cooking a steak until it is well done [blank_start]Physical[blank_end] 9. Burning magnesium ribbon in air [blank_start]Physical[blank_end]

Which of the following is a physical change? Which is a chemical change? burning a piece of wood [blank_start]Chemical change[blank_end] dissolving copper sulfate in water to obtain a blue solution [blank_start]Physical change[blank_end]

State if the following processes is endothermic or exothermic? 1. Heating water from 20°C to 80°C. [blank_start]Endothermic[blank_end] 2. Heating water from 20°C through to boiling continuously at 100°C. [blank_start]Endothermic[blank_end] 3. The burning of a magnesium ribbon in air [blank_start]Endothermic[blank_end] 4. The reaction that takes place when a spark is introduced to a mixture of H2 and O2 gas. [blank_start]Endothermic[blank_end] 5. Any reaction or process that consumes heat energy. [blank_start]Endothermic[blank_end] 6. The process of cooling liquid paradichlorobenzene until it solidifies. [blank_start]Endothermic[blank_end] 7. The decomposition of water into H2 and O2 gas. [blank_start]Endothermic[blank_end] 8. Any reaction or process that releases heat energy [blank_start]Endothermic[blank_end] 9. Condensation of steam [blank_start]Endothermic[blank_end] 10. Sublimation of iodine. [blank_start]Endothermic[blank_end] 11. Vaporization of ethanol [blank_start]Endothermic[blank_end]

Is the following process an endothermic process or exothermic? Ammonium chloride dissolving in water which causes the temperature of the solution to drop [blank_start]Endothermic[blank_end]

In Chemical Reactions which of the following always happens?

How many molecules of nitrogen does one molecule of N2H4 give [blank_start]?[blank_end] (write only in numbers

How many molecules of water does one molecule of N2H4 give [blank_start]....[blank_end] ? write only numbers

How many moles of nitrogen does one mole of N2H4 give [blank_start]...[blank_end] (write only numbers as digits)

How many moles of water does one mole of N2H4 give [blank_start]>[blank_end]

How many grams are there in one mole of N2H4? [blank_start]....[blank_end] g

How many grams are there in three moles of H2 [blank_start]?[blank_end] g