The mass of piece of sterling silver jewelry is 33.24 g. It contains 92.5% silver Ag by mass. Since, sterling silver is an alloy of Ag-Cu thus, percentage of Cu will be:
% Cu=100-92.5=7.5%
Thus, mass of copper will be:

Molar mass of Cu is 63.546 g/mol, thus, number of moles of Cu can be calculated as follows:

Here, m is mass and M is molar mass.
Putting the values,

Now, in 1 mole of Cu there are
thus, in 0.03923 mol, number of Cu atoms will be:

Thus, number of atoms of Cu will be
.
<h2>Answer:</h2>
Option (B):
The products can form reactants, and the reactants can form products.
<h3>Explanation:</h3><h3>Reversible reaction</h3>
A reversible reaction is a reaction where the reactants form products, which react together to give the reactants back.
aA + bB ⇄ cC + dD
A and B can react to form C and D or, in the reverse reaction, C and D can react to form A and B.
Other options are wrong because off:
(A) Concentration changes with time equilibrium concentration and higher product concentration is also possible.
(C) They may be constant.
(D) Concentration changes with time equilibrium concentration and higher reactant concentration is also possible.
3
One from fe
And two from cl2
There are 7 digits from decimal to 1st digit, and it's coming from right, so exponent will be in negative 7
In short, Your Answer would be: Option C) <span>6.75 × 10-7
</span>
Hope this helps!
Answer:
8.76M
Explanation:
Given that
Mass from the density = 1141g
According to the given situation the computation of molarity of the solution is shown below:-
we will took HCL solution which is 1000mL
HCl = 28% by mass
So,
Mass of HCl in 1-litre solution is

Which gives the result of molar mass HCI is
= 319.48g
/mol
Now,
Molarity is

Which gives results of molarity is
= 8.76M