Answer:
endothermic means energy is taken in and temperature increases.
Answer:
Robert Boyle
Explanation:
En muchos textos se suele considerar a Robert Boyle como el científico que introdujo en la Química un concepto de elemento diferente al empleado por los aristotélicos o por los alquimistas y que sirvió de antecedente al que formulara Lavoisier en 1789.
Answer: 
Explanation:
Heat of combustion is the amount of heat released when 1 mole of the compound is completely burnt in the presence of oxygen.

To calculate the moles, we use the equation:
Thus
of sucrose releases = 916.6 J of heat
1 mole of sucrose releases =
of heat
Thus ∆H value for the combustion reaction is 
Answer:
Indeed, the two samples should contain about the same number of gas particles. However, the molar mass of
is larger than that of
(by a factor of about
.) Therefore, the mass of the
sample is significantly larger than that of the
sample.
Explanation:
The
and the
sample here are under the same pressure and temperature, and have the same volume. Indeed, if both gases are ideal, then by Avogadro's Law, the two samples would contain the same number of gas particles (
and
molecules, respectively.) That is:
.
Note that the mass of a gas
is different from the number of gas particles
in it. In particular, if all particles in this gas have a molar mass of
, then:
.
In other words,
.
.
The ratio between the mass of the
and that of the
sample would be:
.
Since
by Avogadro's Law:
.
Look up relative atomic mass data on a modern periodic table:
Therefore:
.
.
Verify whether
:
- Left-hand side:
. - Right-hand side:
.
Note that the mass of the
sample comes with only two significant figures. The two sides of this equations would indeed be equal if both values are rounded to two significant figures.