Answer:
85% of 20 is 17
Explanation:
You can multiply 85% and 20 or subtract 85% from 20.
The reaction;
O(g) +O2(g)→O3(g), ΔH = sum of bond enthalpy of reactants-sum of food enthalpy of products.
ΔH = ( bond enthalpy of O(g)+bond enthalpy of O2 (g) - bond enthalpy of O3(g)
-107.2 kJ/mol = O+487.7kJ/mol =O+487.7 kJ/mol +487.7kJ/mol =594.9 kJ/mol
Bond enthalpy (BE) of O3(g) is equals to 2× bond enthalpy of O3(g) because, O3(g) has two types of bonds from its lewis structure (0-0=0).
∴2BE of O3(g) = 594.9kJ/mol
Average bond enthalpy = 594.9kJ/mol/2
=297.45kJ/mol
∴ Averange bond enthalpy of O3(g) is 297.45kJ/mol.
Answer: 4m/s2 (B)
Explanation:
Force = mass × acceleration
Force given is 8N
Mass=2kg
Acceleration =?
Substitute into the formula
F=ma
8=2a
A=8/2
A=4m/s2
Acceleration used is 4m/s2 (B)
The specific heat of water is higher than the specific heat of concrete.
