Hello!
I'm going to have to infer that you meant "grams" and not "gallons" :-)
Anyways, to find the density, you need to the divide mass over volume (d = m/V).
Since we are given the volume being 15.0 mL, and the weight being 40.5 grams, we can find the density of the aluminum block.
40.5 grams / 15.0 mL = 2.7 g/mL
Therefore, the density of the aluminum block is 2.7 grams per milliliter.
the answer is D. just took the test
The answer is D because it uses the electrical energy from the wall to create heat (Thermal) energy for the clothes
Balanced and Unbalanced Forces
Answer:
54.1 % Ca, 43.2 % O, 2.7% H
Explanation:
Molecular formula for calcium hydroxide is Ca(OH)₂
As we don't have a mass of Ca(OH)₂ to find out the percentage composition, we consider that the question refers to 1 mol of compound.
1 mol of hydroxide weighs 74.08 g
1 mol of hydroxide has 1 mol of Ca, therefore 40.08 g are Ca
2 moles of O therefore 32g are O
2 moles of H therefore 2 g are H
Percentage composition is known as (Mass of element/Total mass) . 100
- (40.08 / 74.08) . 100 = 54.1 %
- (32 / 74.08) . 100 = 43.2 %
- (2 / 74.08) . 100 = 2.7%
