what mass of water must be added to 425g of formaldehyde to prepare a 40.0 solution of formaldehyde

iii.1 Formula Mass and the Mole Concept

1 .

What is the full mass (amu) of carbon in each of the post-obit molecules?

(a) CH₄

(b) CHCl_iii

(c) C₁₂H₁₀O_vi

(d) CH₃CH_twoCH_twoCH₂CH_three

2 .

What is the full mass of hydrogen in each of the molecules?

(a) CH₄

(b) CHCl₃

(c) C₁₂H_xO₆

(d) CH₃CH₂CH_iiCH₂CH₃

3 .

Summate the molecular or formula mass of each of the following:

(a) P₄

(b) H₂O

(c) Ca(NO₃)_ii

(d) CH₃CO₂H (acetic acid)

(e) C₁₂H₂₂O₁₁ (sucrose, cane saccharide)

iv .

Make up one's mind the molecular mass of the following compounds:

(a)

(b)

(c)

(d)

five .

Decide the molecular mass of the following compounds:

(a)

(b)

(c)

(d)

6 .

Which molecule has a molecular mass of 28.05 amu?

(a)

(b)

(c)

7 .

Write a sentence that describes how to make up one's mind the number of moles of a compound in a known mass of the chemical compound using its molecular formula.

8 .

Compare i mole of H₂, 1 mole of O₂, and ane mole of F₂.

(a) Which has the largest number of molecules? Explain why.

(b) Which has the greatest mass? Explicate why.

9 .

Which contains the greatest mass of oxygen: 0.75 mol of ethanol (C₂H₅OH), 0.60 mol of formic acid (HCO₂H), or ane.0 mol of water (H₂O)? Explain why.

10 .

Which contains the greatest number of moles of oxygen atoms: ane mol of ethanol (C₂H_vOH), i mol of formic acid (HCO₂H), or one mol of h2o (H₂O)? Explicate why.

11 .

How are the molecular mass and the molar mass of a compound similar and how are they different?

12 .

Summate the molar mass of each of the post-obit compounds:

(a) hydrogen fluoride, HF

(b) ammonia, NH₃

(c) nitric acid, HNO₃

(d) silver sulfate, Ag_iiAnd so₄

(e) boric acid, B(OH)₃

13 .

Summate the molar mass of each of the post-obit:

(a) S_viii

(b) C₅H₁₂

(c) Sc₂(Then₄)₃

(d) CH₃COCH_three (acetone)

(due east) C_{half dozen}H₁₂O₆ (glucose)

14 .

Calculate the empirical or molecular formula mass and the tooth mass of each of the following minerals:

(a) limestone, CaCO₃

(b) halite, NaCl

(c) beryl, Be₃Al₂Si_sixO₁₈

(d) malachite, Cu_ii(OH)₂CO₃

(e) turquoise, CuAl_{half dozen}(PO_four)₄(OH)₈(H₂O)₄

15 .

Calculate the molar mass of each of the following:

(a) the anesthetic halothane, C_twoHBrClF₃

(b) the herbicide paraquat, C₁₂H₁₄N_iiCl₂

(c) caffeine, C_viiiH_xN₄O₂

(d) urea, CO(NH₂)₂

(e) a typical soap, C₁₇H₃₅CO_iiNa

xvi .

Make up one's mind the number of moles of chemical compound and the number of moles of each type of atom in each of the following:

(a) 25.0 thou of propylene, C₃H_six

(b) three.06 $\times$ x⁻³ g of the amino acrid glycine, C₂H₅NO₂

(c) 25 lb of the herbicide Treflan, C₁₃H_sixteenN₂O₄F (one lb = 454 thousand)

(d) 0.125 kg of the insecticide Paris Green, Cu₄(AsO_three)₂(CH_threeCO₂)₂

(due east) 325 mg of aspirin, C₆H₄(CO₂H)(CO_iiCH₃)

17 .

Determine the mass of each of the following:

(a) 0.0146 mol KOH

(b) ten.2 mol ethane, C₂H₆

(c) 1.six $\times$ x⁻³ mol Na₂ And then_iv

(d) half-dozen.854 $\times$ 10³ mol glucose, C₆ H₁₂ O_six

(e) two.86 mol Co(NH₃)₆Cl_iii

18 .

Determine the number of moles of the compound and make up one's mind the number of moles of each type of cantlet in each of the post-obit:

(a) ii.12 g of potassium bromide, KBr

(b) 0.1488 g of phosphoric acrid, H₃PO₄

(c) 23 kg of calcium carbonate, CaCO₃

(d) 78.452 g of aluminum sulfate, Al₂(And so₄)₃

(eastward) 0.1250 mg of caffeine, C_viiiH₁₀N_fourO₂

19 .

Determine the mass of each of the following:

(a) two.345 mol LiCl

(b) 0.0872 mol acetylene, C₂H_ii

(c) 3.3 $\times$ 10⁻ⁱⁱ mol Na_ii CO_three

(d) 1.23 $\times$ tenⁱⁱⁱ mol fructose, C₆ H₁₂ O_vi

(e) 0.5758 mol FeSO₄(H₂O)₇

20 .

The guess minimum daily dietary requirement of the amino acid leucine, C₆H₁₃NO₂, is i.1 g. What is this requirement in moles?

21 .

Determine the mass in grams of each of the following:

(a) 0.600 mol of oxygen atoms

(b) 0.600 mol of oxygen molecules, O₂

(c) 0.600 mol of ozone molecules, O₃

22 .

A 55-kg woman has 7.v $\times$ 10⁻³ mol of hemoglobin (molar mass = 64,456 g/mol) in her blood. How many hemoglobin molecules is this? What is this quantity in grams?

23 .

Make up one's mind the number of atoms and the mass of zirconium, silicon, and oxygen found in 0.3384 mol of zircon, ZrSiO₄, a semiprecious stone.

24 .

Determine which of the following contains the greatest mass of hydrogen: 1 mol of CH₄, 0.6 mol of C_{half dozen}H₆, or 0.4 mol of C₃H₈.

25 .

Make up one's mind which of the following contains the greatest mass of aluminum: 122 g of AlPO₄, 266 k of Al₂Cl₆, or 225 g of Al₂S_three.

26 .

Diamond is 1 form of elemental carbon. An engagement ring contains a diamond weighing 1.25 carats (i carat = 200 mg). How many atoms are present in the diamond?

27 .

The Cullinan diamond was the largest natural diamond ever constitute (January 25, 1905). It weighed 3104 carats (1 carat = 200 mg). How many carbon atoms were present in the stone?

28 .

One 55-gram serving of a particular cereal supplies 270 mg of sodium, 11% of the recommended daily assart. How many moles and atoms of sodium are in the recommended daily allowance?

29 .

A certain nut crunch cereal contains 11.0 grams of sugar (sucrose, C₁₂H₂₂O_xi) per serving size of 60.0 grams. How many servings of this cereal must be eaten to consume 0.0278 moles of saccharide?

30 .

A tube of toothpaste contains 0.76 g of sodium monofluorophosphate (Na₂PO₃F) in 100 mL.

(a) What mass of fluorine atoms in mg was present?

(b) How many fluorine atoms were present?

31 .

Which of the post-obit represents the least number of molecules?

(a) 20.0 grand of H_iiO (xviii.02 yard/mol)

(b) 77.0 g of CH_four (16.06 g/mol)

(c) 68.0 g of C₃H_six (42.08 yard/mol)

(d) 100.0 chiliad of N₂O (44.02 m/mol)

(e) 84.0 one thousand of HF (20.01 g/mol)

3.2 Determining Empirical and Molecular Formulas

32 .

What information is needed to determine the molecular formula of a chemical compound from the empirical formula?

33 .

Summate the following to iv significant figures:

(a) the percent limerick of ammonia, NH_iii

(b) the percent composition of photographic logroller solution ("hypo"), Na₂Southward₂O_iii

(c) the percent of calcium ion in Ca₃(PO_iv)_ii

34 .

Determine the following to iv meaning figures:

(a) the pct limerick of hydrazoic acid, HN_three

(b) the percent limerick of TNT, C₆H_two(CH_iii)(NO₂)₃

(c) the percent of SO₄ ^2– in Al₂(SO₄)_three

35 .

Make up one's mind the pct ammonia, NH₃, in Co(NH₃)₆Cl_three, to 3 meaning figures.

36 .

Determine the percent water in CuSO_iv∙5H₂O to three significant figures.

37 .

Determine the empirical formulas for compounds with the following percent compositions:

(a) 15.8% carbon and 84.two% sulfur

(b) twoscore.0% carbon, 6.7% hydrogen, and 53.three% oxygen

38 .

Determine the empirical formulas for compounds with the following percent compositions:

(a) 43.6% phosphorus and 56.4% oxygen

(b) 28.vii% K, 1.5% H, 22.8% P, and 47.0% O

39 .

A compound of carbon and hydrogen contains 92.iii% C and has a molar mass of 78.1 m/mol. What is its molecular formula?

forty .

Dichloroethane, a compound that is often used for dry cleaning, contains carbon, hydrogen, and chlorine. It has a molar mass of 99 g/mol. Analysis of a sample shows that information technology contains 24.3% carbon and 4.one% hydrogen. What is its molecular formula?

41 .

Determine the empirical and molecular formula for chrysotile asbestos. Chrysotile has the following pct composition: 28.03% Mg, 21.60% Si, 1.16% H, and 49.21% O. The molar mass for chrysotile is 520.viii 1000/mol.

42 .

Polymers are large molecules composed of simple units repeated many times. Thus, they often take relatively simple empirical formulas. Calculate the empirical formulas of the following polymers:

(a) Lucite (Plexiglas); 59.ix% C, eight.06% H, 32.0% O

(b) Saran; 24.8% C, 2.0% H, 73.1% Cl

(c) polyethylene; 86% C, 14% H

(d) polystyrene; 92.3% C, 7.vii% H

(e) Orlon; 67.9% C, 5.70% H, 26.iv% N

43 .

A major textile dye manufacturer developed a new yellowish dye. The dye has a percent composition of 75.95% C, 17.72% N, and 6.33% H past mass with a molar mass of about 240 thou/mol. Make up one's mind the molecular formula of the dye.

iii.3 Molarity

44 .

Explicate what changes and what stays the aforementioned when one.00 50 of a solution of NaCl is diluted to 1.lxxx L.

45 .

What information is needed to summate the molarity of a sulfuric acid solution?

46 .

A 200-mL sample and a 400-mL sample of a solution of salt take the same molarity. In what ways are the two samples identical? In what ways are these 2 samples unlike?

47 .

Determine the molarity for each of the post-obit solutions:

(a) 0.444 mol of CoCl_ii in 0.654 Fifty of solution

(b) 98.0 g of phosphoric acid, H_threePO₄, in ane.00 L of solution

(c) 0.2074 g of calcium hydroxide, Ca(OH)₂, in 40.00 mL of solution

(d) 10.5 kg of Na₂So₄·10H₂O in eighteen.threescore L of solution

(eastward) 7.0 $\times$ 10⁻³ mol of I₂ in 100.0 mL of solution

(f) 1.8 $\times$ 10^four mg of HCl in 0.075 L of solution

48 .

Determine the molarity of each of the following solutions:

(a) 1.457 mol KCl in i.500 L of solution

(b) 0.515 g of H₂SO₄ in 1.00 50 of solution

(c) 20.54 grand of Al(NO₃)₃ in 1575 mL of solution

(d) ii.76 kg of CuSO₄·5H₂O in 1.45 L of solution

(due east) 0.005653 mol of Br₂ in 10.00 mL of solution

(f) 0.000889 g of glycine, C_twoH₅NO₂, in i.05 mL of solution

49 .

Consider this question: What is the mass of the solute in 0.500 L of 0.30 M glucose, C_{half dozen}H₁₂O₆, used for intravenous injection?

(a) Outline the steps necessary to answer the question.

(b) Reply the question.

50 .

Consider this question: What is the mass of solute in 200.0 L of a i.556-M solution of KBr?

(a) Outline the steps necessary to respond the question.

(b) Answer the question.

51 .

Calculate the number of moles and the mass of the solute in each of the following solutions:

(a) 2.00 L of eighteen.5 M H_iiSO₄, concentrated sulfuric acrid

(b) 100.0 mL of three.eight $\times$ 10^−six M NaCN, the minimum lethal concentration of sodium cyanide in claret serum

(c) five.50 50 of xiii.three Thousand H_iiCO, the formaldehyde used to "prepare" tissue samples

(d) 325 mL of 1.eight $\times$ 10⁻⁶ M FeSO₄, the minimum concentration of atomic number 26 sulfate detectable past gustatory modality in drinking water

52 .

Calculate the number of moles and the mass of the solute in each of the following solutions:

(a) 325 mL of 8.23 $\times$ 10^−five One thousand KI, a source of iodine in the diet

(b) 75.0 mL of 2.2 $\times$ 10⁻⁵ M H₂SO₄, a sample of acrid rain

(c) 0.2500 L of 0.1135 M Grand_twoCrO₄, an analytical reagent used in iron assays

(d) 10.5 L of 3.716 One thousand (NH₄)_iiAnd then₄, a liquid fertilizer

53 .

Consider this question: What is the molarity of KMnO₄ in a solution of 0.0908 yard of KMnO_iv in 0.500 L of solution?

(a) Outline the steps necessary to answer the question.

(b) Answer the question.

54 .

Consider this question: What is the molarity of HCl if 35.23 mL of a solution of HCl contain 0.3366 g of HCl?

(a) Outline the steps necessary to answer the question.

(b) Answer the question.

55 .

Calculate the molarity of each of the following solutions:

(a) 0.195 one thousand of cholesterol, C₂₇H₄₆O, in 0.100 L of serum, the average concentration of cholesterol in homo serum

(b) 4.25 yard of NH_iii in 0.500 L of solution, the concentration of NH₃ in household ammonia

(c) 1.49 kg of isopropyl booze, C₃H₇OH, in two.l L of solution, the concentration of isopropyl alcohol in rubbing alcohol

(d) 0.029 g of I₂ in 0.100 L of solution, the solubility of I₂ in h2o at 20 °C

56 .

Calculate the molarity of each of the following solutions:

(a) 293 k HCl in 666 mL of solution, a concentrated HCl solution

(b) ii.026 g FeCl₃ in 0.1250 L of a solution used equally an unknown in general chemical science laboratories

(c) 0.001 mg Cd^two+ in 0.100 L, the maximum permissible concentration of cadmium in drinking water

(d) 0.0079 1000 C₇H₅SNO₃ in one ounce (29.half dozen mL), the concentration of saccharin in a diet soft beverage.

57 .

There is about i.0 m of calcium, as Ca²⁺, in 1.0 L of milk. What is the molarity of Ca²⁺ in milk?

58 .

What volume of a 1.00-G Fe(NO₃)₃ solution can exist diluted to prepare 1.00 Fifty of a solution with a concentration of 0.250 1000?

59 .

If 0.1718 L of a 0.3556-M C₃H₇OH solution is diluted to a concentration of 0.1222 One thousand, what is the book of the resulting solution?

60 .

If 4.12 L of a 0.850 M-H_threePO₄ solution is be diluted to a volume of x.00 L, what is the concentration of the resulting solution?

61 .

What volume of a 0.33-M C₁₂H₂₂O_eleven solution can be diluted to prepare 25 mL of a solution with a concentration of 0.025 G?

62 .

What is the concentration of the NaCl solution that results when 0.150 L of a 0.556-One thousand solution is allowed to evaporate until the book is reduced to 0.105 L?

63 .

What is the molarity of the diluted solution when each of the post-obit solutions is diluted to the given final volume?

(a) 1.00 L of a 0.250-Thou solution of Fe(NO_three)_three is diluted to a final volume of 2.00 50

(b) 0.5000 L of a 0.1222-M solution of C_threeH_sevenOH is diluted to a final book of 1.250 L

(c) ii.35 L of a 0.350-K solution of H₃PO₄ is diluted to a concluding book of 4.00 50

(d) 22.50 mL of a 0.025-G solution of C₁₂H₂₂O_xi is diluted to 100.0 mL

64 .

What is the final concentration of the solution produced when 225.5 mL of a 0.09988-Thou solution of Na_twoCO_iii is allowed to evaporate until the solution volume is reduced to 45.00 mL?

65 .

A 2.00-L bottle of a solution of concentrated HCl was purchased for the full general chemical science laboratory. The solution independent 868.8 k of HCl. What is the molarity of the solution?

66 .

An experiment in a general chemical science laboratory calls for a ii.00-M solution of HCl. How many mL of 11.9 K HCl would be required to make 250 mL of 2.00 M HCl?

67 .

What volume of a 0.20-Thou K₂Then₄ solution contains 57 g of Thousand_twoSO_iv?

68 .

The Usa Environmental Protection Agency (EPA) places limits on the quantities of toxic substances that may be discharged into the sewer system. Limits accept been established for a multifariousness of substances, including hexavalent chromium, which is express to 0.fifty mg/L. If an industry is discharging hexavalent chromium as potassium dichromate (K₂Cr₂O₇), what is the maximum permissible molarity of that substance?

3.4 Other Units for Solution Concentrations

69 .

Consider this question: What mass of a full-bodied solution of nitric acid (68.0% HNO_iii by mass) is needed to fix 400.0 g of a 10.0% solution of HNO_three by mass?

(a) Outline the steps necessary to answer the question.

(b) Respond the question.

seventy .

What mass of a iv.00% NaOH solution by mass contains 15.0 g of NaOH?

71 .

What mass of solid NaOH (97.0% NaOH past mass) is required to prepare ane.00 50 of a x.0% solution of NaOH past mass? The density of the 10.0% solution is one.109 m/mL.

72 .

What mass of HCl is contained in 45.0 mL of an aqueous HCl solution that has a density of 1.xix one thousand cm^–3 and contains 37.21% HCl by mass?

73 .

The hardness of water (hardness count) is usually expressed in parts per million (by mass) of CaCO₃, which is equivalent to milligrams of CaCO₃ per liter of water. What is the molar concentration of Caⁱⁱ⁺ ions in a water sample with a hardness count of 175 mg CaCO₃/L?

74 .

The level of mercury in a stream was suspected to be above the minimum considered safe (1 function per billion past weight). An assay indicated that the concentration was 0.68 parts per billion. Presume a density of 1.0 thousand/mL and calculate the molarity of mercury in the stream.

75 .

In Canada and the Uk, devices that measure claret glucose levels provide a reading in millimoles per liter. If a measurement of 5.iii thousandM is observed, what is the concentration of glucose (C₆H₁₂O_{half dozen}) in mg/dL?

76 .

A throat spray is 1.forty% by mass phenol, C_viH_vOH, in water. If the solution has a density of 0.9956 g/mL, calculate the molarity of the solution.

77 .

Copper(I) iodide (CuI) is often added to tabular array salt equally a dietary source of iodine. How many moles of CuI are contained in i.00 lb (454 g) of tabular array salt containing 0.0100% CuI by mass?

78 .

A cough syrup contains v.0% ethyl alcohol, C_twoH_fiveOH, by mass. If the density of the solution is 0.9928 g/mL, make up one's mind the molarity of the booze in the cough syrup.

79 .

D5W is a solution used as an intravenous fluid. It is a five.0% past mass solution of dextrose (C₆H₁₂O₆) in water. If the density of D5W is 1.029 grand/mL, calculate the molarity of dextrose in the solution.

80 .

Notice the molarity of a 40.0% past mass aqueous solution of sulfuric acid, H₂SO_four, for which the density is i.3057 m/mL.

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Source: https://openstax.org/books/chemistry-2e/pages/3-exercises

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