Why did you post this again? Because you're lazy and wanted people to not see my post? Once again, ONE QUESTION AT A TIME. We're here to help you with a tough question or work you through it, not do all your homework.
Answer:
Explanation:
Our
sample yielded 1g of
and 16g of
, but our unknown sample yielded 2 times as much
for the same amount of
.
What does this mean? that the H:O proportion for the unknown sample is twice the H:O proportion for the
sample.
What is the H:O proportion for the
sample? As we can see from its formula, it's 1:1, therefore the proportion for the unknown formula must be 2:1.
That means, two H atoms for every O atom. We could write that as:
and you should recognize that formula, for it is one of the most common compounds on earth, Water.
Answer: The enthalpy of combustion, per mole, of butane is -2657.4 kJ
Explanation:
The balanced chemical reaction is,
The expression for enthalpy change is,
Putting the values we get :
2 moles of butane releases heat = 5314.8 kJ
1 mole of butane release heat = 
Thus enthalpy of combustion per mole of butane is -2657.4 kJ
Answer:
1. Venus
471°C
2. Mercury
(430°C) during the day, (-180°C) at night
3. Earth
16°C
4. Mars
-28°C
5. Jupiter
-108°C
6. Saturn
-138°C
7. Uranus
-195°C
8. Neptune
-201°C
Explanation:
.
Answer:
(d) burning a log.
(b) toasting a slice of bread;
Explanation:
Chemical change -
A chemical change refers to , the change in which a new compound is formed .
From the question ,
Its is not a chemical process , since no new compound is formed , these is only change in state as the liquid is turning to gaseous sate .
It is not a chemical process , as no new substance is formed .
- toasting a slice of bread
It is a chemical change , in which bread surface is deposited by a brown coat via the process of heating , even this process is a irreversible in nature .
It is a chemical change , as with the help of heating , the wood is turning to ashes .