Answer: The activation energy is 10 kJ and the reaction is exothermic.
Explanation: Exothermic reactions are those in which heat is released and thus the energy of products is less than the energy of reactants.
Endothermic reactions are those in which heat is absorbed and thus the energy of products is more than the energy of reactants.
Activation energy is the extra amount of energy required by the reactants to cross the energy barrier to convert to products.
Given : Energy of reactants = 40kJ
Energy of activation: (50-40)=10 kJ
Energy of products = 50 kJ
Energy of products = 15 kJ
Thus Energy of products (15kJ) < Energy of reactants(40kJ), the reaction is exothermic as energy has been lost to surroundings in the form of heat.
Molar mass <span>Aluminium ( Al) = 26.98 g/mol
1 mole ------------ 26.98 g
? mole ----------- 2.98 g
moles Al = 2.98 x 1 / 26.98
moles Al = 2.98 / 26.98
= 0.110 moles
hope this helps!
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830 mL. A 2.3 mol/L solution of CaCl2 has a volume of 830 mL
I am guessing that the concentration of your solution is 2.3 mol/L.
a) Moles of CaCl2
MM of CaCl2 = 110.98 g/mol
Moles of CaCl2 = 212 g CaCl2 x (1 mol CaCl2/110.98 g CaCl2)
= 1.910 mol CaCl2
b) Volume of solution
V = 1.910 mol CaCl2 x (1 L solution/2.3 mol CaCl2) = 0.83 L solution
= 830 mL solution
Answer:
The percentage of N in the compound is 0.5088
Explanation:
Mass of compound = 8.75 mg = 8.75×1000 = 8750 g
Mass of N2 = number of moles of N2 × MW of N2 = 1.59 × 28 = 44.52 g
% of N in the compound = (mass of N2/mass of compound) × 100 = (44.52/8750) × 100 = 5.088×10^-3 × 100 = 0.5088