When you want to melt an ice, you only need the latent energy of fusion, <span>δhfus. We use the given value, then multiply this with the given amount to determine the amount of energy. Since the energy is per mole basis, use the molar mass of ice which is 18 g/mol. The solution is as follows:
</span>ΔH = 5.96 kJ/mol * 1 mol/18 g * 500 g
<em>ΔH = 165.56 kJ</em><span>
</span>
Bleaching hair i a physical change i think; it washes the pigments out.
i hope this helps (;
Answer: option A) Mixtures may be composed of two or more elements, two or more compounds, or a combination of both.
Explanation:
A mixture is a combination of two or more substances mixed together and can be separated by physical methods.
A combination of two elements or compounds will yield chemical compounds NOT a mixture.
Thus, option A is false statement
Answer:
0.0025 M/min
Explanation:
The rate of a reaction can be calculated for an element, based on its stoichiometric coefficient. For a reaction:
aA + bB = cC + dD , the rate will be
r = -(1/a)x(Δ[A]/Δt) = -(1/b)x(Δ[B]/Δt) = (1/c)x(Δ[C]/Δt) = (1/d)x(Δ[D]/Δt)
Where Δ[X] is the variation of the concentration of the X compound, Δt is the time variation, and the signal of minus in the reagents compounds is because they are disappearing, so Δ[X] will be negative, and r must be positive. So, for the reaction given:
r = -(1/2)x(Δ[NO]/Δt)
r = -(1/2)x( (0.025 - 0.1)/15)
r = 0.0025 M/min
