CHEM LAB

Question 1

what are the parts of the bunsen burner and their functions?

Answer 1

• Barrel: where combustion takes place (air and fuel mix)
• Gas outlet: controls the amount of gas that enters the barrel at a great speed due to the tiny opening
• collar: opens and closes the air hole, regulates the amount of air that enters the bunsen burner.
  -Air hole: where the air enters the bunsen burner
• Flame Regulator: controls the height of the flame
• Gas inlet: controls the amount of fuel entering the bunsen burner. Where the rubber tubing is attached
• Base: supports the entire apparatus

Question 2

Why is it necessary to check for holes and cracks on rubber tubings before using them?

Answer 2

to avoid gas leaks which can cause serious damage to the human body.

Question 3

AIR HOLE IS CLOSED

Answer 3

yellow; luminous flame; incomplete combustion

Question 4

What is the chemical equation of an incomplete combustion?

Answer 4

C4H10 (g) + 402 (g) – CO2 (g) + 5H20 (g) + CO (g) + 2C (s) + heat

Question 5

What happens to the bottom of the evaporating dish after putting it on top of a LUMINOUS flame

Answer 5

produces black soot. This is because you produced a carbon.

Question 6

AIR HOLE OPEN

Answer 6

blue; non-luminous flame; complete combustion

Question 7

chemical equation of a complete combustion

Answer 7

2C4H10 (g) + 13O2 (g) – 8CO2 (g) + 10H2O (g) + heat

Question 8

What happens to the bottom of the evaporating dish after putting it on top of a NON LUMINOUS flame

Answer 8

not much change. only produced carbon dioxide and water vapor.

Question 9

DIFFERENT REGIONS OF FLAME AND THEIR TEMPERATURES AND COLORS

Answer 9

• OUTER REGION: pale violet (1540 Celsius)
• CENTER REGION: intense blue )1560 celsius)
• INNER REGION: pale blue (500-300 celsius)

Question 10

What is a glass rod used for?

Answer 10

guide the flow of the liquid transferring from one container to another

Question 11

why should only the upper portion of the water on the test tube be heated?

Answer 11

avoid spillage. splashing of liquids

Question 12

what is precipitation?

Answer 12

chemical reaction where insoluble liquid called precipitate is formed.

Question 13

balanced equation that happened during heating liquids of the test tube

Answer 13

BaCI2 + NAO2S4 – BASO4 + 2NaCI

Question 14

what type of liquid is formed in precipitation

Answer 14

white curdy liquid

Question 15

chemical name after precipitation

Answer 15

barium sulfate

Question 16

What is the purpose of filtration

Answer 16

to separate the solid components from a liquid mixture,

Question 17

substance left called

Answer 17

residue

Question 18

What is the chemical name left in the filer paper

Answer 18

barium sulfate

Question 19

what is the substance that drained through the filter paper

Answer 19

colorless solution

Question 20

liquid drained through the filter paper

Answer 20

filtrate

Question 21

chemical name of the liquid that when through the filter paper

Answer 21

sodium chloride

Question 22

what are the substances formed in the evaporating dish under evaporation

Answer 22

sodium chloride crystals (white residue)

Question 23

chemical name of the substance left in the evaporating dish? (evaporation)

Answer 23

sodium chloride

Question 24

other product from evaporation?

Answer 24

water vapor

Question 25

What is the appropriate liquid that was poured off during decantation?

Answer 25

supernatant liquid

Question 26

what is the smell from ammonia? (NH3)

Answer 26

firecrackers

Question 27

RED: ____
BLUE: ____

Answer 27

ACIDIC
NEUTRAL

Question 28

• VINEGAR
• DISHWASHING LIQUID
• NA2SO4 SOLUTION
• TAP WATER
• DISTILLED WATER

Answer 28

• Stays red, turns red= Acidic
• turns blue, stays blue= Base
• stays red, styas blue= neutral
• stays red, turns red= neutral
• stays red, turns red= neutral