Alkaline solutions are basic so answer is C basic
Answer:
Electric engines have efficiencies of roughly 90% whilst combustion engines about 10% to 30%. This is because combustion engines emit much more heat, which is always energy that is not used as work, and thus increases inefficiency.
Explanation:
Answer:
1. A
2. C
Explanation:
For the first question, we know that the water transformed into a gas. This fact eliminates choices C and D, primarily because they describe the change as "gas to liquid" instead of liquid to gas.
What separates B from A is that B is saying the liquid changed to a gas in response to sunlight, which is completely false and impertinent to the prompt.
A is the correct answer.
for the second question, we know that condensation causes clouds -- and that neither evaporation nor water vapor would clear clouds to make more of them, which eliminates choices B and D. Going back to condensation, the accumulation of water vapor plays a big role in the formation of clouds. While evaporation does play a part in [it] as well, condensation is what caused the sudden appearance of clouds in the troposphere.
C is the correct answer.
Answer:
Molarity of Na₂CO₃ = 0.25M
% mass = 2.69
Explanation:
Molarity means mole of solute in 1L of solution
Molar mass of solute (Na₂CO₃) = 105,98 g/m
Moles = mass / molar mass → 6.73 g / 105.98 g/m = 0.0635 m
Mol/L = [M]
0.0635 mol/0.250L = 0.25M
Density of solution = Solution mass / Solution volume
1 g/ml = Solution mass / 250 mL → Solution mass is 250g
% mass will be:
In 250 g of solution we have 6.73 g of solute
in 100 g of solution we have (100 . 6.73)/250 = 2.69
Answer:
b
Explanation:
[H3O+] = 10-pH = 10-3.4 ≅ 3.981 x 10^-4 moles/liter
