Answer:
2Mg + O₂ ⟶ 2MgO
Explanation:
Step 1. Start with the most complicated-looking formula (O₂?).
Put a 1 in front of it.
Mg + 1O₂ ⟶ MgO
Step 2. Balance O.
We have fixed 2 O on the left. We need 2O on the right. Put a 2 in front of MgO.
Mg + 1O₂ ⟶ 2MgO
Step 3. Balance Mg.
We have fixed 2 Mg on the right-hand side. We need 2 Mg atoms on the left. Put a 2 in front of Mg.
2Mg + 1O₂ ⟶ 2MgO
Every formula now has a coefficient. The equation should be balanced. Let’s check.
<u>Atom</u> <u>On the left</u> <u>On the righ</u>t
Mg 2 2
O 2 2
All atoms are balanced.
The balanced equation is
2Mg + O₂ ⟶ 2MgO
% Composition = ?
no atom in 2 g of styrene =?
molar mass of strene =104.15
% composition of c= 12/13.008 =.922*100=92.2
% composition of h =1.008/13.008=0.0774*100= 7.74
no gram atom=mass in kg /molar mass=2/104.15 =0.01920 mol
no of gram atom * avogadro's number = 0.0192*6.02 *10( exponent 23) =1.15584
This is an oxidation reduction reaction
oxidation happens when the species gives out electrons.Oxidation state of the element Cu increases from 0 to +2
Cu ---> Cu²⁺ +2e --1)
Reduction happens when the species gains electrons.
Oxidation state of N reduces from +5 to +2
4H⁺ + NO₃⁻ + 3e ---> NO + 2H₂O --2)
To balance the reactions, number of electrons need to be balanced.
Multiply 1st reaction by 3
Multiply 2nd reaction by 2
3Cu ---> 3Cu²⁺ + 6e
8H⁺ + 2NO₃⁻ + 6e ---> 2NO + 4H₂O
add the 2 equations
3Cu + 8H⁺ + 2NO₃⁻ --> 3Cu²⁺ + 2NO + 4H₂O
add 6NO₃⁻ ions to each side
3Cu + 8HNO₃ --> 3Cu(NO₃)₂ + 2NO + 4H₂O
the balanced redox reaction equation is as follows;
3Cu(s) + 8HNO₃(aq) --> 3Cu(NO₃)₂ (aq)+ 2NO(g) + 4H₂O(l)
In order to balance this, you have to count each
element where the elements in the reactants side and the product side should
have equal number of molecules. The balanced reaction is as follows:
2HCl + Ca(OH)2 = CaCl2 + 2H2O
Answer:
1. Two to decompose
Explanation:
It's going to be a decomposition so you can eliminate answers 3 and 4. It is a decomposition because it is splitting apart. Then you can figure out that it is going to be two instead of four by balancing the equation
H2O2 → 2H2O + O2
