Answer:between 25 and 40 degrees Fahrenheit
Explanation:
Heat pumps do not operate as efficiently when temperatures drop to between 25 and 40 degrees Fahrenheit for most systems. A heat pump works best when the temperature is above 40. Once outdoor temperatures drop to 40 degrees, heat pumps start losing efficiency, and they consume more energy to do their jobs.
Thus, one atom of carbon will combine with two atoms of oxygen to form the molecule CO 2 ( carbon dioxide ). (b) From the chemical formula of the compound aluminium oxide Al 2 O 3 , the valency of aluminium can be determined. ... Hence the valency of aluminium is 3
Explanation:
In the extreme winters , the water inside pipes freeze, on freezing it's(water molecule) density decreases and volume increases and therefore, the ice then expands and pushes the water towards the faucet, causing high pressure buildup in the pipe and after a limit the pipe burst. This is what happened to the family in Ottawa, where winters are chilly.
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%
