Higher chemitry

3CuO + 2NH3 ↓ 3Cu + N2 + 3H2O
What volume of gas, in cm3
, would be obtained by reaction between 100 cm3
of ammonia
gas and excess copper(II) oxide?
All volumes are measured at atmospheric pressure and 20 °C.
A 50
B 100
C 200
D 400

Answer is A, Somehow managed to get C, could someone please help me?

Ok so from the question I can gather that theres 100cm3 of ammonia and due to the 3 : 2 mole ratio there is therefore 150cm3 of CuO, I then used this to find 150cm3 of Cu and 50cm3 of N2.

The only way I could think it's A is because Cu and N2 are solids and so dont count when I'm counting the gases and therefore only the 50cm3 of CuO count so A? Is that right?

So you have the calculation correct but you’ve got a bit muddled in your reasoning.

CuO :copper oxide, a solid @20*C
The ammonia is all used up

Cu is a solid so doesn’t count
H2O is liquid at 20*C so doesn’t count
N2 is dinitrogen which is a gas at 20*C

And you already calculated that it makes 50cm of N2 = Answer A

So you have the calculation correct but you’ve got a bit muddled in your reasoning.

CuO :copper oxide, a solid @20*C
The ammonia is all used up

Cu is a solid so doesn’t count
H2O is liquid at 20*C so doesn’t count
N2 is dinitrogen which is a gas at 20*C

And you already calculated that it makes 50cm of N2 = Answer A

Is there a way to know what state an element is at a certain temperature? Just for next time.

Is there a way to know what state an element is at a certain temperature? Just for next time.

I think they would just expect you to know these.

You have a metal oxide, a metal, water and nitrogen.

What level are you at?

the electric motor in the car is powered by a battery. To charge the battery, the car is plugged into the mains supply at 230v. The power used to charge the battery is 6.9KW. Calculate the current used to charge the battery.

current= ????? A


I have this question for my homework its for physics a level but its a gcse question.... Could someone please help me ?

the electric motor in the car is powered by a battery. To charge the battery, the car is plugged into the mains supply at 230v. The power used to charge the battery is 6.9KW. Calculate the current used to charge the battery.

current= ????? A


I have this question for my homework its for physics a level but its a gcse question.... Could someone please help me ?

I've seen you post this question on like 3 different threads already ahaha.

Is it not just P=IV ?

im sure its current in amps= charge in coulombs divided by time in seconds or i= q divided by t

but dont know how to work it out ddhd

Lad we don't need to use Q=IT at all in this question - Q or T aren't mentioned anywhere! P = IV is the key to success here

lad??? and AGHHH could you explain it for me PLEASE ddjjd i need to write how i got it

lad??? and AGHHH could you explain it for me PLEASE ddjjd i need to write how i got it

I literally just gave you the equation to use...