Answer:
0.55 mol Au₂S₃
Explanation:
Normally, we would need a balanced equation with masses, moles, and molar masses, but we can get by with a partial equation, if the S atoms are balanced.
1. Gather all the information in one place:
M_r: 34.08
Au₂S₃ + … ⟶ 3H₂S + …
m/g: 56
2. Calculate the moles of H₂S
Moles of H₂S = 56 g H₂S × (34.08 g H₂S/1 mol H₂S)
= 1.64 mol H₂S
3. Calculate the moles of Au₂S₃
The molar ratio is 1 mol Au₂S₃/3 mol H₂S.
Moles of Au₂S₃ = 1.64 mol H₂S × (1 mol Au₂S₃/3 mol H₂S)
= 0.55 mol Au₂S₃
A chemical reaction (signs)
- rusting
- change in base of chemical
- for example lets say u mix two chemicals, and then it becomes a different new chemical (it changed from the inside)
a physical
- a physical reaction is outer looks not inside.
- it changes on the outside, like changing a color
Answer:
Answer:
step 1:balance skeleton equation the chemical equation:
Zn +HNO3➔Zn(NO3)2+NO+H2O
step 2: identity undergoing oxidation or reduction
here
Zn➔Zn(NO3)2
Zn is oxidized from 0 to 2 in oxidation no.
HNO3➔NO
N is reduced from 5 to 2 in oxidation no
Step 3: calculate change in oxidation no.
change in oxidation no
in Zn=0-2=-2=2
in
N=5-2=3
Step 4: Balance it by doing crisscrossed multiplication
we get;
3Zn +2HNO3➔3Zn(NO3)2+2NO+H2O
step 6:Balance other atoms except H & O
3Zn +2HNO3➔3Zn(NO3)2+2NO+H2O
3Zn +2HNO3+6HNO3➔3Zn(NO3)2+2NO+H2O
finally: balance H
<em><u>3Zn +8HNO3➔3Zn(NO3)2+2NO+4H2O</u></em>
To work this out you do 400÷20=20
