Answer:
51 J
Explanation:
The air inside a bicycle tire pump has 27 joules of heat conducted away. By convention, when heat is released, it takes the negative sign, so Q = -27 J.
77.9 joules of work done are being done on the air inside a bicycle tire pump. By convention, when work is being done on the system, it takes the positive sign, so W = 77.9 J
We can calculate the change in the internal energy (ΔU) using the following expression.
ΔU = Q + W
ΔU = (-27 J) + 77.9 J
ΔU = 51 J
Answer:
C
Explanation:
The substance would be classified as neutral, so C.
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.
The question above can be solved by using this equation:
CAVA =CBVB
Where:
CA =Concentration of acid = 1.0 M
VA = Volume of acid = ?
CB = Concentration of base = 1.0 M
VB = Volume of base = 25 ml
VA = CBVB / CA
VA = [1 * 25] / 1 = 25 / 1 = 25
VA = 25 ml
Therefore, the volume of acid that is required to completely neutralize the base is 25 ml.<span />
Answer:
Explanation:
The melting point of a substance is the temperature at which its melt. The state of a substance is dependent on it's melting temperature. Generally, melting point above 25 °C is a solid.
This means phenol is a solid
Duodecane has melting point below 25 °C hence it is either a liquid or gas. However its boiling point of 216 °C means it would require higher temperature to boil it. Since 25 °C is less than 216 °C it means that it would remain in the liquid state.
Methane has melting point below 25 °C hence it is either a liquid or gas. However its boiling point of -164 °C means it boils easily even at very low temperatures. Since 25 °C is greater than -164 °C it means that it would exist in the gaseous state