Answer:
731.25 g
Explanation:
The question asks us to calculate the mass of 12.5 moles of NaCl. The individual relative atomic masses of the elements were supplied. We must first obtain the molar mass of sodium chloride as follows;
Molar mass of sodium chloride= 23.0 + 35.5 = 58.5 gmol-1
From the formula;
Number of moles (n) = mass /molar mass
Number of moles of sodium chloride= 12.5 moles
Mass of sodium = The unknown
Molar mass of sodium chloride= 58.5gmol-1
Mass of sodium chloride= number of moles × molar mass
Mass of sodium chloride= 12.5 × 58.5
Mass of sodium chloride= 731.25 g
44. (a) N2O3 (b) SF4 (c) AlCl3 (d) Li2CO3
46. H Br
δ+ δ−
48. The metallic potassium atoms lose one electron and form +1 cations,
and the nonmetallic fluorine atoms gain one electron and form –1 anions.
K → K+
+ e–
19p/19e–
19p/18e–
F + e–
→ F–
9p/9e–
9p/10e–
The ionic bonds are the attractions between K+
cations and F–
anions.
50. See Figure 3.6.
52. (a) covalent…nonmetal-nonmetal (b) ionic…metal-nonmetal
54. (a) all nonmetallic atoms - molecular (b) metal-nonmetal - ionic
56. (a) 7 (b) 4
58. Each of the following answers is based on the assumption that nonmetallic
atoms tend to form covalent bonds in order to get an octet (8) of
electrons around each atom, like the very stable noble gases (other than
helium). Covalent bonds (represented by lines in Lewis structures) and lone
pairs each contribute two electrons to the octet.
(a) oxygen, O
If oxygen atoms form two covalent bonds, they will have an octet of electrons
around them. Water is an example:
H O H
(b) fluorine, F
If fluorine atoms form one covalent bond, they will have an octet of electrons
around them. Hydrogen fluoride, HF, is an example:
H F
(c) carbon, C
If carbon atoms form four covalent bonds, they will have an octet of electrons
around them. Methane, CH4, is an example:
H H
H
H
C
(d) phosphorus, P
If phosphorus atoms form three covalent bonds, they will have an octet
Answer:
it is A trust me I know thank you
Above it says the molecular weights are
NH3- 17g/mol and SF6-146 g/mol
Well 1 mole of SF6 is 146.048 grams (i added hte atomic masses of each element). So then the number of moles in 0.85 grams would be 0.00582000438 moles.
<span><span><span>= 1mole / </span><span>146.048g *</span></span> 0.85g</span>
so we would need 0.00582000438 moles of NH3 to have the same number of molecules.
One mole of NH3 is 17.030519999989988 grams (i added each atoms mass). so 0.00582000438 moles of NH3 would be:
<span><span><span>= 17.030519999989988 g / </span><span>mole * </span></span>0.00582000438moles</span>
that equals 0.09911770099 grams.
so 0.09911770099 grams is the answer if you round that you get about 0.1 grams
