Among the choices, the polyatomic ion is only the third choice, NH4+ where it is composed of nitrogen one atom of nitrogen and 4 atoms of hydrogen. Choice 2 is a monoatomic atom being composed only of calcium. Then, the first and fourth choices are not ions because they are not charged.
1.78L x (3.00M/1L) = 5.34
Answer:
(a) 
(b) 
(c) 
Explanation:
Hello,
(a) In this case, since entropy remains unchanged, the constant
should be computed for air as an ideal gas by:


Next, we compute the final temperature:

Thus, the work is computed by:

(b) In this case, since
is given, we compute the final temperature as well:

And the isentropic work:

(c) Finally, for isothermal, final temperature is not required as it could be computed as:

Regards.
Answer:
ok 3 = 9 15 i got 15 so what
Explanation:
Molar mass Mg = 24.3 g/mol
1 mole mg ------------ 24.3 g
?? moles mg --------- 4.75 g
4.75 x 1 / 24.3 => 0.195 moles of Mg
hope this helps!