ðŸŽ‰ The Study-to-Win Winning Ticket number has been announced! Go to your Tickets dashboard to see if you won! ðŸŽ‰View Winning Ticket

University of Maine

Problem 1
Problem 2
Problem 3
Problem 3
Problem 4
Problem 5
Problem 6
Problem 7
Problem 8
Problem 9
Problem 10
Problem 11
Problem 12
Problem 13
Problem 14
Problem 15
Problem 16
Problem 17
Problem 18
Problem 19
Problem 20
Problem 21
Problem 22
Problem 23
Problem 24
Problem 25
Problem 26
Problem 27
Problem 28
Problem 29
Problem 30
Problem 31
Problem 32
Problem 33
Problem 34
Problem 35
Problem 36
Problem 37
Problem 38
Problem 39
Problem 40
Problem 41
Problem 42
Problem 43
Problem 44
Problem 45
Problem 46
Problem 47
Problem 48
Problem 49
Problem 50
Problem 51
Problem 52
Problem 53
Problem 54
Problem 55
Problem 56
Problem 57
Problem 58
Problem 59
Problem 60
Problem 61
Problem 62
Problem 63
Problem 64
Problem 65
Problem 66
Problem 67
Problem 68
Problem 69
Problem 70
Problem 71
Problem 72
Problem 73
Problem 74
Problem 75
Problem 76
Problem 77
Problem 78
Problem 79
Problem 80
Problem 81
Problem 82
Problem 83
Problem 84
Problem 85
Problem 86
Problem 87
Problem 88
Problem 89
Problem 90
Problem 91
Problem 92
Problem 93
Problem 94
Problem 95
Problem 96
Problem 97
Problem 98
Problem 99
Problem 100
Problem 101
Problem 102
Problem 103
Problem 104
Problem 105
Problem 106
Problem 107
Problem 108
Problem 109
Problem 110
Problem 111
Problem 112
Problem 113
Problem 114
Problem 115
Problem 116
Problem 117
Problem 118
Problem 119
Problem 120
Problem 121
Problem 122
Problem 123
Problem 124
Problem 125
Problem 126
Problem 127
Problem 128
Problem 129
Problem 130
Problem 131
Problem 132
Problem 133
Problem 134
Problem 135
Problem 136
Problem 137
Problem 138
Problem 139
Problem 140

Problem 16

Calculate each of the following quantities:

(a) Mass (g) of $6.44 \times 10^{-2} \mathrm{mol}$ of $\mathrm{MnSO}_{4}$

(b) Amount (mol) of compound in 15.8 $\mathrm{kg}$ of $\mathrm{Fe}\left(\mathrm{ClO}_{4}\right)_{3}$

(c) Number of $\mathrm{N}$ atoms in 92.6 $\mathrm{mg}$ of $\mathrm{NH}_{4} \mathrm{NO}_{2}$

Answer

a) $\mathrm{m}=9,725 \mathrm{g}$

b) $\mathrm{n}\left(\mathrm{Fe}\left(\mathrm{ClO}_{4}\right)_{3}\right)=44,61 \mathrm{mol}$

c) $\mathrm{N}(\mathrm{N})=1,74^{*} 10^{21}$ atoms

You must be logged in to bookmark a video.

...and 1,000,000 more!

OR

## Discussion

## Video Transcript

When you're given a quantity either mass moles or Adams, it's helpful to create a road map where a plan to change from one to another they all are the same amount. They're just being measured in different units. If you have mass, you can change two moles by using the molar mass. Remember, the molar mass is found using the periodic table and the molar mass. The atomic masses, the number below each element. So to find the molar mass of anything, we simply add up the molar masses of those. So if you have mass and you want to go to moles, you divide by Moeller Mass. If you have moles and you want to go to Mass, you multiply by the molar mass. If, instead of looking at Mass, you're looking at atoms or molecules or particles we use of a God rose number. If you have Adams and you want to change to moules, you can divide by other Godric's numbers. If you have moles to Adams, you multiply by offer God rose number. You can also go from Masto Adams, or vice versa, always changing two moles first. So, for example, we have a certain amount of moles of a substance six point 44 times 10 to the minus tube nos of mn eso for we want to know how many grams that equals. We're starting at moles and changing to mass, so we need to multiply by the molar mass. So we have malls that we multiply my molar mass to get grams to find the molar mass. We use the periodic table, and we look up the molar mass of each substance. Do we have the mass of MN, which is 54 0.938 plus the mass of sulfur, which is 32.0 six? It was four times the mass of oxygen, and this gives us a total Mueller math of 151 2000 grams per mole. Where to find the equivalent, we multiply 6.44 times, 10 to the minus two nos. For every one mole, it is equal to 151.0 grams, so this has a mass of 9.72 grams. You could start instead with a mass. So, let's say, 15.8 kilograms of a substance F E Cielo for three and change it to moles. So if we have mass kilograms, we need to change it to mass in grams. And then we need to change two moles. And we do that by knowing that one kilogram is equal to 1000 grams. We use our Moeller Mass, so we have 15.8 kilograms. We change it to grams by multiplying by 1000 a man to change two moles we multiplied by the Moeller math. So one more, Um and using your periodic table, you find the molar mass of the substance to be 354 0.20 grams. So we take 15.8 times 1000 divided by 354.20 You find that it's equivalent to 44.6 mol Another example in which you have to be careful of looking at what the question is asking is if we have a certain mass of a substance. So 92.6 milligrams, uh, NH for ANO, too. And we want to know how many Adams of nitrogen are present in this compound. So we have a molecule and we're looking at the number of nitrogen atoms using the formula, so we'll start off with milligrams, which we have to change two grams. Once we have grams, we can change two moles. Once we have moles of our compound, we can change two molecules of the compound and then using the chemical formula, we can find the number of atoms of nitrogen. So to go from milligrams two grams, we know there are 1000 milligrams and everyone Graham from grams to moles will use the molar mass from moles to molecules we use of a god rose number. And then finally we used the chemical formula to see how many atoms there are in every molecule. So 92.6 milligrams for every one gram. There are 1000 milligrams. Using the periodic table, we find the molar mass and everyone mall of this substance has a molar mass of 92.6, 64 64 point 06 grams. Then every mole we know there are 6.2 times 10 to the 23rd molecules. And finally, if we look at the formula, there are two nitrogen atoms for every one molecule. So by multiplying 92.6 times 6.2 times 10 to the 23rd times two and then dividing by 1000 times 64.6 You see that there are 1.74 times 10 to the 21st Adams of nitrogen.

## Recommended Questions

Calculate each of the following quantities:

(a) Mass ( $\mathrm{g}$ ) of 0.68 $\mathrm{mol}$ of $\mathrm{KMnO}_{4}$

(b) Amount (mol) of $\mathrm{O}$ atoms in 8.18 $\mathrm{g}$ of $\mathrm{Ba}\left(\mathrm{NO}_{3}\right)_{2}$

(c) Number of $\mathrm{O}$ atoms in $7.3 \times 10^{-3} \mathrm{g}$ of $\mathrm{CaSO}_{4} \cdot 2 \mathrm{H}_{2} \mathrm{O}$

Calculate each of the following quantities:

(a) Amount (mol) of Mn atoms in 62.0 $\mathrm{mg}$ of Mn

(b) Amount (mol) for $1.36 \times 10^{22}$ atoms of $\mathrm{Cu}$

(c) Mass ( g) of $8.05 \times 10^{24}$ Li atoms

Calculate each of the following quantities:

(a) Total number of ions in 38.1 $\mathrm{g}$ of $\mathrm{SrF}_{2}$

(b) Mass $(\mathrm{kg})$ of 3.58 $\mathrm{mol}$ of $\mathrm{CuCl}_{2} \cdot 2 \mathrm{H}_{2} \mathrm{O}$

(c) Mass $(\mathrm{mg})$ of $2.88 \times 10^{22}$ formula units of $\mathrm{Bi}\left(\mathrm{NO}_{3}\right)_{3} \cdot 5 \mathrm{H}_{2} \mathrm{O}$

Calculate each of the following quantities:

(a) Mass (g) of 8.42 mol of chromium(III) sulfate decahydrate

(b) Mass $(\mathrm{g})$ of $1.83 \times 10^{24}$ molecules of dichlorine heptoxide

(c) Amount (mol) and number of formula units in 6.2 $\mathrm{g}$ of lithium sulfate

(d) Number of lithium ions, sulfate ions, sulfur atoms, and oxygen atoms in the mass of compound in part (c)

Calculate the molar mass for each of the following:

a. $\mathrm{O}_{2}$

b. $\mathrm{KH}_{2} \mathrm{PO}_{4}$

c. $\mathrm{Fe}\left(\mathrm{ClO}_{4}\right)_{3}$

d. $\mathrm{C}_{4} \mathrm{H}_{8} \mathrm{O}_{4}$

e. $\mathrm{Ga}_{2}\left(\mathrm{CO}_{3}\right)_{3}$

Determine the formula mass and molar mass of each of the following compounds:

a) ${XeF}_{4}$

b) ${C}_{12} {H}_{24} {O}_{6}$

c) ${Hg}_{2} {I}_{2}$

d) ${CuCN}$

Calculate the number of moles of the indicated substance present in each of the following samples.

a. 21.2 g of ammonium sulfide

b. 44.3 g of calcium nitrate

c. 4.35 g of dichlorine monoxide

d. 1.0 lb of ferric chloride

e. 1.0 $\mathrm{kg}$ of ferric chloride

Calculate the number of moles of the indicated substance present in each of the following samples.

a. 1.28 $\mathrm{g}$ of iron(II) sulfate

b. 5.14 $\mathrm{mg}$ of mercury(II) iodide

c. 9.21$\mu \mathrm{g}$ of tin(IV) oxide

d. 1.26 $\mathrm{lb}$ of cobalt(II) chloride

e. 4.25 $\mathrm{g}$ of copper(II) nitrate

Calculate the molar mass for each of the following substances.

a. sodium nitride, $\mathrm{Na}_{3} \mathrm{N}$

b. carbon disulfide, $\mathrm{CS}_{2}$

c. ammonium bromide, $\mathrm{NH}_{4} \mathrm{Br}$

d. ethyl alcohol, C_ $\mathrm{H}_{5} \mathrm{OH}$

e. sulfurous acid, $\mathrm{H}_{2} \mathrm{SO}_{3}$

f. sulfuric acid, $\mathrm{H}_{2} \mathrm{SO}_{4}$

Calculate the mass in grams of each of the following samples.

a. $1.27 \times 10^{-3}$ mol of carbon dioxide

b. $4.12 \times 10^{3}$ mol of nitrogen trichloride

c. 0.00451 mol of ammonium nitrate

d. 18.0 mol of water

e. 62.7 mol of copper (II) sulfate