Question

Hey,new to chemistry. Can i have some help? Thanks

Answer 1

hey, what's your question?

Answer 2

Which of the following is a chemical change
Mixing chalkpowder with sand
Melting of ice
Dissolving sugar in water
Cooking an egg

Answer 3

its easy i knowww

Answer 4

any thoughts so far?

as a reminder, a chemical change occurs when the chemical identity of a compound changes.

so out of the 4 choices which one do you think changes the substance into something chemically different?

Answer 5

the egg?

Answer 6

good! the cooked egg is chemically distinct from the raw egg so cooking the egg is a chemical change. the others are physical changes.

Answer 7

thx

Answer 8

another is

Answer 9

Pre-ignition of the fuel is seen in _________
petrol knocking
petrol cracking
diesel cracking
diesel knocking

Answer 10

i can get these

Answer 11

oh, I don't know much about engines, we can try to research the terms though

Answer 12

here

Answer 13

im gonna try to do smt

Answer 14

Pre-ignition is a situation in which the fuel-air mixture in a spark ignition engine ignites before the timed spark, because of contact with a hot surface. Over-heated spark plugs and exhaust valves are the main causes of pre-ignition. Pre-ignition might be the consequence of the spark plug tip getting too hot.

Answer 15

petrol knocking?

Answer 16

YAY-