Explanation:
Burning fossil fuels, changing land use, and using limestone to make concrete all transfer significant quantities of carbon into the atmosphere
Empirical formula is the simplest ratio of components making up a compound.
The percentage composition of each element has been given
therefore the mass present of each element in 100 g of compound is
B N H
mass 40.28 g 52.20 g 7.53 g
number of moles
40.28 g / 11 g/mol 52.20 g / 14 g/mol 7.53 g / 1 g/mol
= 3.662 mol = 3.729 mol = 7.53 mol
divide the number of moles by the least number of moles, that is 3.662
3.662 / 3.662 3.729 / 3.662 7.53 / 3.662
= 1.000 = 1.018 = 2.056
the ratio of the elements after rounding off to the nearest whole number is
B : N : H = 1 : 1 : 2
therefore empirical formula for the compound is B₁N₁H₂
that can be written as BNH₂
Answer:

Explanation:
There are no molecules in NaCl, because it consists only of ions.
However, we can calculate the number of formula units (FU) of NaCl.
Step 1. Calculate the moles of NaCl

Step 2. Convert moles to formula units

There are
in 3.6 g of NaCl.
The reaction that has the greatest tendency to be reversed in an spontaneous redox reaction is that whose forward standard reduction potential is the lowest (mos negative) one because that means that the reversed reaction will have the highest (most positive) standard reduction potential.
So, the answer is Cr(3+) + 3e- ---> Cr(s) with Eo = -0.91 V, whose reversed reaction is Cr(s) - 3e- ---> Cr (3+) with Eo = +0.91 V.
Answer: the second option Cr(3+) + 3e- ---> Cr(s) Eo = -0.91 V