Answer:
B
Explanation:
the pH scale is based on the function
1x10-14
So since pH is neutral the concentration of OH and H must be equal hence the only option in which the concetration would [OH]{H}= 1x10-14 would be when both are equal so it cannot be a or d and when they are expressed in concetration so the only option is B.
Answer:- 335 kcal of heat energy is produced.
Solution:- The balanced equation for the combustion of glucose in presence of oxygen to give carbon dioxide and water is:

From given info, 2803 kJ of heat is released bu the combustion of 1 mol of glucose. We need to calculate the energy produced when 3.00 moles of oxygen react with excess of glucose.
We could solve this using dimensional analysis as:

= 1401.5 kJ
Now, let's convert kJ to kcal.
We know that, 1kcal = 4.184kJ
So, 
= 335 kcal
Hence, 335 kcal of heat energy is produced by the use of 3.00 moles of oxygen gas.
Smaller atoms and stronger bonds promotes greater hardness in minerals.
Volume of a substance can be determined by dividing mass of the substance by its density.
That can be mathematical shown as:
Density=Mass/Volume
So, Volume=Mass/Density
Here mass of the substance given as 24.60 g
Whereas density of the substance is 2.70 g/mL
So,
Volume=Mass/Density
=24.6/2.7
=9.1 mL
So volume of the substance is 9.1 mL.
no because they are two diffrent things