Determine the mass of each of the following:
(a)0.0146 mol koh
(b)10.2 mol etane, c2h6
(c)1.6 x 10-3 mol na2so4
(d)6.854 x 103 mol glucose, c6 h12 o6
(e)2.86 mol co(nh3)6 cl3

A) 0.82 g

B) 306 g

C) 0.23 g

D) g

E) 764 g

Explanation:

A) Upon consulting a periodic table one can find the atomic masses of each element present at a given molecule.

H=1.00 g/mol K=39.10 O=16.00

By adding the masses of the atoms in a molecule, we get its molecular weight.

KOH molecular mass is 1.00+39.10+16 = 56.10 g/mol

 Therefore the mass in 0.0146 mol of KOH is:

56.10 g/mol x 0.0146 mol = 0.82 g

B) Upon consulting a periodic table one can find the atomic masses of each element present at a given molecule.

H=1.00 g/mol C=12.01

By adding the masses of the atoms in a molecule, we get its molecular weight.

C2H6 molecular mass is 6x1.00+2x12.01= 30.02 g/mol

 Therefore the mass in 10.2 mol of KOH is:

30.02 g/mol x 10.2 mol = 306 g

C) Upon consulting a periodic table one can find the atomic masses of each element present at a given molecule.

Na=22.99 g/mol S=32.07 O=16.00

By adding the masses of the atoms in a molecule, we get its molecular weight.

Na2SO4 molecular mass is 2x22.99+32.07+4x16.00=142.05 g/mol

 Therefore the mass in 0.0016 mol of Na2SO4  is:

142.05 g/mol x 0.0016 mol = 0.23 g

D) Upon consulting a periodic table one can find the atomic masses of each element present at a given molecule.

H=1.00 g/mol C=12.01  O=16.00

By adding the masses of the atoms in a molecule, we get its molecular weight.

 C6H12O6 molecular mass is 16x1.00+6x12.01+6x16.00= 184.06 g/mol

 Therefore the mass in 6854 mol of C6H12O6 is:

184.06 g/mol x 6854 mol = g

E) Upon consulting a periodic table one can find the atomic masses of each element present at a given molecule.

H=1.00 g/mol Cl=35.45 g/mol Co=58.93 g/mol N=14.01 g/mol

By adding the masses of the atoms in a molecule, we get its molecular weight.

 Co(NH3)6 Cl3 molecular mass is 58.93+6x14.01+18x1.00+3x35.45=267.34 g/mol

 Therefore the mass in 2.86 mol of Co(NH3)6 Cl3 is:

267.34 g/mol x 2.86 mol = 764 g

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.  

the answer is b because, investigating whether another species of moth also drinks tears might be interesting, but it would not directly explain why this species of moth does.

to explain why this species of moth drinks tears, the scientist could ask: "what nutrients that moths need are in elephant tears? "

the scientist could experiment with moth repellent or oter ways to keep the moths away, but that would not answer his original question.