Answer:
= 67.79 g
Explanation:
The equation for the reaction is;
4Cr(s)+3O2(g)→2Cr2O3(s)
The mass of O2 is 21.4 g, therefore, we find the number of moles of O2;
moles O2 = 21.4 g / 32 g/mol
=0.669 moles
Using mole ratio, we get the moles of Cr2O3;
moles Cr2O3 = 0.669 x 2/3
=0.446 moles
but molar mass of Cr2O3 is 151.99 g/mol
Hence,
The mass Cr2O3 = 0.446 mol x 151.99 g/mol
<u> = 67.79 g
</u>
the mass percent of sugar in this solution is 46%.
Answer:
Solution given:
mass of solute=34.5g
mass of solvent=75g
mass percent=
=
Answer:
The statement true is A. A and B are isotopes of the same element.
Explanation:
Isotopes correspond to atoms of the same element with different mass numbers (A), that is to say they differ in the amount of neutrons in the nucleus. In the case of compound A it has 10 neutrons, and B has 11.
<h3>
Answer</h3>
HF
<h3>Explanation</h3>
A buffer solution contains <em>a weak acid</em> and<em> its conjugate base</em>. The two species shall have a similar concentration in the solution. It's also possible for <em>a weak base</em> and <em>its conjugate acid</em> to form a buffer solution.
The KF solution already contains large number of
ions. The objective is to thus find its conjugate acid or base.
contains no proton
and is unlikely to be a conjugate acid. Assuming that
is a conjugate base. Adding one proton to
would produce its conjugate acid.

Therefore
is the conjugate acid of
.
happens to be a weak acid. As a result, combining
with
would produce a solution with large number of both the weak acid and its conjugate base, which is a buffer solution by definition.