Answer:
A
Explanation:
No temperature change was observed, hence the change is neither exothermic nor endothermic. Hence the answer is A.
A layer of greenhouse gases – primarily water vapor, and including much smaller amounts of carbon dioxide, methane and nitrous oxide – acts as a thermal blanket for the Earth, absorbing heat and warming the surface to a life-supporting average of 59 degrees Fahrenheit (15 degrees Celsius).
The molecular mass of carbon monoxide (CO) is 28 g/mol
<u><em>calculation</em></u>
The molecular mass of CO = atomic mass of C + atomic mass of O
From periodic table the atomic mass of C = 12 g/mol and for O = 16 g/mol
Therefore the molecular mass of Co = 12 g/mol + 16 g/mol = 28 g/mol
Answer:
pH = 1.5
Explanation:
The pH is always equal to -log[H+].
Simply plug it into this formula to find the pH. In order to find the concentration from the pH, you can do:
= [H+]
The correct option is D.
In chemistry, a pure substance refers to a matter that possesses definite and constant composition with unique chemical properties. Another word for a pure substance is chemical substance. A pure substance typically contains only one type of atom or only one type of molecule. Examples of pure substances are water, sodium chloride, gold, silver, etc. In the question given above, we are told that the unknown element can only be broken down by chemical mean, this shows that the unknown compound is a chemical compound.
