<u>Answer:</u> The true statements are for an endothermic reaction is positive, a combustion reaction is exothermic and when energy is transferred as heat from the system to the surroundings, is negative.
<u>Explanation:</u>
There are 2 types of chemical reactions categorized into heat change:
- <u>Endothermic reactions:</u> These reactions are defined as the reactions in which energy is absorbed by the system from the surroundings. The for these reactions is always positive. For Example: Changing of water into water vapor.
- <u>Exothermic reactions:</u> These reactions are defined as the reactions in which energy is released by the system to the surroundings. The for these reactions is always negative. For Example: Combustion reactions.
Combustion reactions are defined as the reactions in which a hydrocarbon reacts with oxygen gas to produce carbon dioxide and water. Heat is released during these reactions. Thus, it is considered as exothermic reactions.
Hence, the true statements are for an endothermic reaction is positive, a combustion reaction is exothermic and when energy is transferred as heat from the system to the surroundings, is negative.
Answer:
C. AgNO3 + LICI - AgCl + LINO3
Explanation:
Here the chemical equation for double displacement reaction is
AgNO3 + LICI - AgCl + LINO3
The reaction in which two compounds react together to form two other compounds by mutual exchange of their ions is called double displacement reaction.
Hope it will help :)
Answer:
Explanation:
= Volume of NaOH = 34.56 mL
= Volume of HCl = 25 mL
= Concentration of NaOH = 0.25 M
= Concentration of HCl
When endpoint is reached the number of moles of NaOH will be equal to the number of moles of HCl
Concentration of HCl is .
Answer:
A
Explanation:
I would assume A because it says in the problem statement that chooses aluminum because he is worried that composite will suddenly fail... therefore he would use aluminum because it would bend before breaking and therefore show warning.