A. A pacemaker
Hope this helps!
Mass percentage of a solution is the amount of solute present in 100 g of the solution.
Given data:
Mass of solute H2SO4 = 571.3 g
Volume of the solution = 1 lit = 1000 ml
Density of solution = 1.329 g/cm3 = 1.329 g/ml
Calculations:
Mass of the given volume of solution = 1.329 g * 1000 ml/1 ml = 1329 g
Therefore we have:
571.3 g of H2SO4 in 1329 g of the solution
Hence, the amount of H2SO4 in 100 g of solution= 571.3 *100/1329 = 42.987
Mass percentage of H2SO4 (%w/w) is 42.99 %
Answer;
= 0.054 kg or 54 g
Explanation;
Using the equation; Q = mcΔT where Q is the quantity of heat transferred, m is the mass, c is specific heat of the substance, ΔT is delta T, the change in temperature.
ΔT = 75 - 20 = 55 C.
Solve the equation for m
m = Q/ cΔT
Mass = 12500 / (55 × 4200)
= 0.054 kg or 54 g
D. Two electrons in its first energy level; eight electrons in its second energy level; six valence electrons in its outermost energy level.
Please correct me if I'm wrong!! :)