% COMPOSITION Flashcards by jayjay ogogog

An unknown compound with a composition of 27.7 % magnesium (Mg), 23.6% phosphorus (P), and 48.7% oxygen (O). Determine the empirical formula. (atomic masses: Mg = 24.3 g/mol; P = 31.0g/mol; O = 16.0g/mol)

Mg3(PO4)2

How well did you know this?

Not at all

Perfectly

A senior high school student found a compound to contain 42.1% sodium (Na), 18.9% phosphorus (P), and 39.0% oxygen (O). What is the empirical formula of the compound? (atomic masses: Na = 23.0g/mol; P = 31.0g/mol; O = 16.0g/mol)

Na3PO4

How well did you know this?

Not at all

Perfectly

Ethanol is an important industrial chemical; it is used as a solvent, in the synthesis of other organic chemicals, and as an additive to automotive gasoline (forming a mixture known as a gasohol). Compute for the percentage of carbon in ethanol.

52.14%

How well did you know this?

Not at all

Perfectly

A lab specialist analyzed and found a compound that contains 16.78% calcium, 29.67% chlorine, and 53.56% oxygen. What is the chemical name of the compound? (atomic masses (g/mol): Ca = 40.10; Cl = 35.45; O = 16.0)

CALCIUM PERCHLORATE

How well did you know this?

Not at all

Perfectly

In medicine, calcium bicarbonate is sometimes administered intravenously to immediately correct the cardiac depressor effects of hyperkalemia by increasing calcium concentration in serum, and at the same time, correcting the acid usually present. Calculate the percent by mass of oxygen in calcium bicarbonate? (atomic masses (g/mol): Ca = 40.10; H = 1.01; C = 12.0; O = 16.0)

59.3%

How well did you know this?

Not at all

Perfectly

A compound is analyzed and found to contain 56.58%K, 8.69%C, and 34.73%O. What is the chemical name of the compound? (atomic masses : K = 39.1g/mol; C = 12.0g/mol; O = 16.0g/mol)

POTASSIUM CARBONATE

How well did you know this?

Not at all

Perfectly

A lab technician made a research for a compound that contains 22.1% aluminum (Al), 25.4% phosphorus (P), and 52.5% oxygen (O). What is the empirical formula? (atomic masses : Al = 27.0g/mol; P = 31.0g/mol; O = 16.0g/mol)

AlPO4

How well did you know this?

Not at all

Perfectly

Calculate the percent composition of cesium in cesium chlorate? (Cs=132.9g/mol; Cl=35.45g/mol; O=16.0g/mol)

61.4%

How well did you know this?

Not at all

Perfectly

A strip of electrolytically pure copper weighing 3.178 grams is strongly heated in a stream of oxygen until it is all converted to 3.978 grams of the black oxide? Compute for the percentage of copper.

79.9%

How well did you know this?

Not at all

Perfectly

20.1%

How well did you know this?

Not at all

Perfectly

A 10.0 grams sample of a crude ore contains 2.80 grams of HgS. What is the percentage of mercury in the ore? (Hg=200.59g/mol; S=32.07g/mol)

24.1%

How well did you know this?

Not at all

Perfectly

What weight of CuO will be required to furnish 200. kg copper? (Cu = 63.5g/mol; O=16.0g/mol)

250 KG

How well did you know this?

Not at all

Perfectly

What weight of silver is present in 3.45 grams of silver sulfide?

3.00 GRAMS

How well did you know this?

Not at all

Perfectly

A compound is analyzed and found to contain 15.78 % Al, 56.11 % O, and 28.11% S. What is the chemical name of the compound? (Al=27.0g/mol; O=16.0g/mol; S=32.1g/mol)

ALUMINUM SULFATE

How well did you know this?

Not at all

Perfectly

The purest form of carbon is prepared by decomposing pure sugar,(driving off water). What is the maximum number of grams of carbon that could be obtained from 1.00 lb of sugar (454 g = 1lb)

191 GRAMS

How well did you know this?

Not at all

Perfectly

A compound is analyzed and found to contain 77.27 %U, 10.4 %O, and 12.3%F. What is the empirical formula? (U=238g/mol; O=16.0g/mol; F=19.0g/mol)

UO2F2

How well did you know this?

Not at all

Perfectly

Find the percentage of arsenic in a polymer using the image below. (C=12.0g/mol; H=1.00g/mol; As=74.9g/mol; B = 10.8g/mol)

C2H8AsB

63.6%

How well did you know this?

Not at all

Perfectly

A famous scientist tries to conduct an experiment about a compound containing 16.3 % C; 32.1 % Cl and 51.6 % F. (C=12.0g/mol; Cl=35.45g/mol; F=19.0g/mol)

C3Cl2F6

How well did you know this?

Not at all

Perfectly

A young handsome scientist made an experiment for a compound that contains 65.04% silver, 15.67 % chromium and 19.29 % oxygen. What is the chemical formula of the compound? (silver=107.9g/mol; chromium=52.0g/mol; oxygen=16.0g/mol)

AG2CrO4

How well did you know this?

Not at all

Perfectly

A handsome farmer wants to know the nitrogen content (fertilizer rating) available in ammonium nitrate.(N=14.0g/mol; H=1.00g/mol; O=16.0g/mol)

35.0%

How well did you know this?

Not at all

Perfectly

What is the nitrogen content in ammonium sulfate? (N=14.0g/mol; H=1.00g/mol; S=32.1g/mol; O=16.0g/mol)

21.2%

A young scientist made an experiment for a compound that contains 88.8% copper and 11.2 % oxygen. (copper=63.5g/mol; oxygen=16.0g/mol)

Cu2O3

A STEM -Strand senior high school student took an experiment for a compound that contains 38.7 % Ca, 20.0 % P and 41.3 % oxygen. What is the chemical name of the unknown compound?(Ca=40.1g/mol; P=31.0g/mol; O=16.0g/mol)

CALCIUM PHOSPHATE

A famous scientist tries to conduct an experiment about a compound containing 21.6 % Mg; 21.4 % C and 57.0 % O. What is the chemical name of the compound? (Mg=24.3g/mol; C=12.0g/mol; O=16.0g/mol)

MAGNESIUM OXALATE

A senior high school student took an experiment for a compound that contains 39.97 % carbon, 13.41 % hydrogen and 46.62 % nitrogen. Find the molecular formula of the compound if the molecular mass is equal to 60.0 grams/mole. (carbon=12.0g/mol; hydrogen=1.00g/mol; nitrogen=14.0g/mol)

CaH4N

A senior high school student took an experiment for a compound that contains 39.97 % carbon, 13.41 % hydrogen and 46.62 % nitrogen. What is the empirical formula. (carbon=12.0g/mol; hydrogen=1.00g/mol; nitrogen=14.0g/mol)

CH4N

A young chemists made an experiment for a compound that contains 33.25 % Fe, 38.18% S, and 28.57% O. What is the chemical name of the compound? (Fe=55.9g/mol; S=32.1g/mol; O=16.0g/mol)

FERROUS THIOSULFATE

A young chemists made an experiment for a compound that contains 33.25 % Fe, 38.18 % S, and 28.57 % O. what is the empirical mass of the compound? (Fe=55.9g/mol; S=32.1g/mol; O=16.0g/mol)

168.1 GRAMS/MOLE

A senior high school student made an experiment for a compound that contains 41.7% Mg, 54.9% O, and 3.40% H. What is the molecular formula if the molecular mass of the compound is equal to 116.6g/mol? (Mg=24.3g/mol; O=16.0g/mol; H=1.00g/mol)

MgO2H2

A scientist conducts an experiment for a compound that contains 32.4 % Na, 22.6 % S, and 45.0 % O. What is the chemical name of the compound? (Na=23.0g/mol; S=32.1g/mol; O=16.0g/mol)

SODIUM SULFATE

Chemical analysis indicates it is composed of 40.68% carbon, 5.08% hydrogen, and 52.24% oxygen and has a molar mass of 118.1 g/mol. Determine the empirical and molecular formulas for this compound.

EMPIRICAL FORMULA: C2H3O2 MOLECULAR FORMULA: C4H6O4

Determine the empirical formula for methyl acetate, which has the following chemical analysis: 48.64% carbon, 8.16% hydrogen, and 43.20% oxygen.

EMPIRICAL FORMULA: C3H6O2

Aspirin has the molecular formula C9H8O4. C = 12.0 ; H = 1.01 ; O = 16.0

Sugar Glucose (C6H12O6) C = 12.0 ; H = 1.01 ; O = 16.0

Baking powder (sodium bicarbonate) Na = 23.0 ; C = 12.0 ; H = 1.01 ; O = 16.0

Milk of magnesia (magnesium hydroxide) Mg = 24.0 ; H = 1.01 ; O = 16.0

Ammonia N = 14.0 ; H = 1.01

Glycerol (C3H8O3) C = 12.0 ; H = 1.01 ; O = 16.0

Blue vitrol (copper (II) sulfate) Cu = 63.5 ; S = 32.0 ; O = 16.0

Borax (sodium tetraborate pentahydrate) Na2B4O7 × 5 H2O Na = 23.0 ; B = 10.8 ; O = 16.0 ; H = 1.01

Gypsum (calcium sulfate dihydrate) Ca = 40.0 ; S = 32.0 ; O = 16.0 ; H = 1.01

Washing soda (sodium carbonate decahydate) Na = 23.0 ; C = 12.0 ; O = 16.0 ; H = 1.01

A compound is found to consist of 7.81% C and 92.19% Cl. What is the empirical and molecular formula of the compound? (C = 12.0 ; Cl = 35.5)

A compound is found to consist of 43.64% P and 56.36% O. The molar mass for the compound is 283.88 g/mol. What is the empirical formula and molecular formula of the compound? (P = 31.0 ; O = 16.0)

A compound is analyzed and found to contain 68.54% carbon, 8.63% hydrogen, and 22.83% oxygen. The molecular weight of this compound is known to be approximately 140 g/mol. What is the empirical formula? What is the molecular formula? (C = 12.0 ; H = 1.01 ; O = 16.0 )

Caffeine has the following percent composition: carbon 49.48%, hydrogen 5.19%, oxygen 16.48% and nitrogen 28.85%. Its molecular weight is 194.19 g/mol. What is its molecular formula? (C= 12.0 ; H = 1.01 ; O = 16.0 ; N = 14.0)

Ammonia reacts with phosphoric acid to form a compound that contains 28.2% nitrogen, 20.8% phosphorous, 8.1% hydrogen and 42.9% oxygen. Calculate the empirical formula of this compound. (N = 14.0 ; P = 31.0 ; H = 1.01 ; O = 16.0 ;)

A compound contains 57.54% C, 3.45% H, and 39.01% F. What is its empirical formula? (C = 12.0 ; H = 1.01 ; F = 19.0 ;)

Halothane is an anesthetic that is 12.17% C, 0.51% H, 40.48% Br, 17.96% Cl and 28.87% F by mass. What is the compound's molar mass if each molecule contains exactly one hydrogen atom? (C = 12.0 ; H = 1.01 ; Br = 79.9 ; Cl = 35.5 ; F = 19.0 ;)

A compound is found to have 1.121 g N, 0.161 g H, 0.480 g C and 0.640 g O. What is its empirical formula? (N = 14.0; H = 1.01; C = 12.0; O = 16.0)

A 15.67 g sample of a hydrate of magnesium carbonate was heated, without decomposing the carbonate, to drive off the water. The mass was reduced to 7.58 g. What is the formula of the hydrate? (Mg =24.3; C = 12.0; O = 16.0 H =1.01)

A hydrate of Na2CO3 has a mass of 4.31 g before heating. After heating, the mass of the anhydrous compound is found to be 3.22 g. Determine the formula of the hydrate and then write out the name of the hydrate. (Na = 23.0; C = 12.0; H = 1.01; O = 16.0)