measurement&experimental techniques

Question 1

apparatus to measure mass?

Answer 1

electronic mass balance (to measure the mass of substances)

Question 2

apparatus to measure time?

Answer 2

stopwatch (sor)

Question 3

apparatus to measure temperature?

Answer 3

thermometer (temperature changes)

Question 4

what is a beaker for?

Answer 4

volume estimation of liquids

Question 5

what is a measuring cylinder for?

Answer 5

volume estimation of liquids to the nearest cm3 (more accurate than beaker)

Question 6

what is pipette for?

Answer 6

to measure fixed volumes of liquid accurately (nearest .0cm3)

Question 7

what is a burette for?

Answer 7

measures out the volume of a liquid to the nearest 0.05cm3 accurately (0.05, 0.80)

Question 8

what is a gas syringe for?

Answer 8

measure volume of gas produced

Question 9

what does the method of gas collection depend on?

Answer 9

it depends on the solubility and density of the gas

Question 10

what is displacement of water for?

Answer 10

gases that are insoluble in water or slightly soluble in water
eg. hydrogen, co2. oxygen

Question 11

what is upward delivery for?

Answer 11

gases that are less dense than air
eg. hydrogen, ammonia, methane

Question 12

what is downward delivery for?

Answer 12

gases that are denser than air
eg. chlorine, hydrogen chloride, co2. sulfur dioxide

Question 13

how tell if a gas is less dense than air?

Answer 13

relative molecular mass<29

Question 14

can upward and downward delivery be used for gases that are insoluble in water?

Answer 14

yes

Question 15

what is drying of gases?

Answer 15

it involves removing water vapour so that we can obtain a purer sample of the gas