Answer:
3 g/mL
Explanation:
We know that the density of an object can be measured by dividing its mass (g) to its volume (mL).
Formula
D=m/v
Given data:
Mass= 45 g
Volume= 15 mL
Now we will put the values in formula:
D=45 g/ 15 mL= 3 g/mL
Answer:
25.7 kJ/mol
Explanation:
There are two heats involved.
heat of solution of NH₄NO₃ + heat from water = 0
q₁ + q₂ = 0
n = moles of NH₄NO₃ = 8.00 g NH₄NO₃ × 1 mol NH₄NO₃/80.0 g NH₄NO₃
∴ n = 0.100 mol NH₄NO₃
q₁ = n * ΔHsoln = 0.100 mol * ΔHsoln
m = mass of solution = 1000.0 g + 8.00 g = 1008.0 g
q₂ = mcΔT = 58.0 g × 4.184 J°C⁻¹ g⁻¹ × ((20.39-21)°C) = -2570.19 J
q₁ + q₂ = 0.100 mol ×ΔHsoln – 2570.19 J = 0
ΔHsoln = +2570.19 J /0.100 mol = +25702 J/mol = +25.7 kJ/mol
Answer:
36.51%.
Explanation:
First find the percentage of iron in pure Fe2O3 using the atomic masses of the elements:
= (2 * 55.845) * 100 / (2*55.845+ 3*15.999)
= 69.94 %.
So the percentage of iron in the mixture
= 52.2 * 0.6994
= 36.51 (answer).
A strong acid like HCl donates its proton so readily that there is essentially no tendency for the conjugate base Cl– to reaccept a proton. Consequently, Cl– is a very weak base.
