Answer:
Explanation:
The relative atomic mass of an element is a weighted average of the masses of the atoms of the isotopes - because if there is much more of one isotope then that will influence the average mass much more than the less abundant isotope will.
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.
<em>c</em> = 1.14 mol/L; <em>b</em> = 1.03 mol/kg
<em>Molar concentration
</em>
Assume you have 1 L solution.
Mass of solution = 1000 mL solution × (1.19 g solution/1 mL solution)
= 1190 g solution
Mass of NaHCO3 = 1190 g solution × (7.06 g NaHCO3/100 g solution)
= 84.01 g NaHCO3
Moles NaHCO3 = 84.01 g NaHCO3 × (1 mol NaHCO3/74.01 g NaHCO3)
= 1.14 mol NaHCO3
<em>c</em> = 1.14 mol/1 L = 1.14 mol/L
<em>Molal concentration</em>
Mass of water = 1190 g – 84.01 g = 1106 g = 1.106 kg
<em>b</em> = 1.14 mol/1.106 kg = 1.03 mol/kg
A sour-tasting material (usually in a solution) that dissolves metals and other materials. Technically, a material that produces positive ions in solution. An acid<span> is the opposite of a base and has a pH of 0 to 7.</span>