Chemistry Chemistry Practice Problems Solutions Library

Mole Concept Solutions Library

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928 solutions

Mole Concept

Q. The experimentally measured and generally accepted value for the molar volume of Na is about 23 cm3 /mol. Which of the following best explains why ...

Solved • Jul 2, 2020

Mole Concept

Q. Using your answer from Part A, calculate the volume of a mole of Na atoms (in cm3 /mol). Assume that the entire volume is occupied by Na atoms leav...

Solved • Jul 2, 2020

Mole Concept

Q. How many molecules are contained in a 7.50-g sample of dimethylmercury?Express your answer in molecules to three significant figures.Alkyl derivati...

Solved • Jul 1, 2020

Mole Concept

Q. Part B. Calculate the formula mass of ethanol, C2H5OH.The formula mass (sometimes called formula weight) of a substance is determined by summing th...

Solved • Jul 1, 2020

Mole Concept

Q. Part A. What is the formula mass of Mg(NO3)2?The formula mass (sometimes called formula weight) of a substance is determined by summing the atomic ...

Solved • Jul 1, 2020

Mole Concept

Q. The fuel used in many disposable lighters is liquid butane, C4H10. How many carbon atoms are in 3.00 g of butane?You can extend the analysis to sam...

Solved • Jul 1, 2020

Mole Concept

Q. Calculate the mass of 1.00 × 1024 (a septillion) molecules of water.You can extend the analysis to samples of a given mass using the molar mass of ...

Solved • Jul 1, 2020

Mole Concept

Q. A flask contains 0.500 mol of liquid bromine, Br2. Determine the number of bromine molecules present in the flask.Express your answer numerically i...

Solved • Jul 1, 2020

Mole Concept

Q. How many oxygen atoms are in 3.50 g of quartz?Matter is made up atoms, but in a real chemistry lab, we measure substances in grams. Therefore you n...

Solved • Jul 1, 2020

Mole Concept

Q. Part B. How many silicon-30 atoms are found in this plate? Express your answer numerically using two significant figures.Monel metal is a corrosion...

Solved • Jul 1, 2020

Mole Concept

Q. Based on your answer in Part B, how many neutrons are in this amount of 13C? Express your answer numerically in neutrons.The mole (abbreviated mol)...

Solved • Jul 1, 2020

Mole Concept

Q. Based on your answer in Part B, how many electrons are in this amount of 13C? Express your answer numerically in electrons.The mole (abbreviated mo...

Solved • Jul 1, 2020

Mole Concept

Q. Based on your answer in Part A, calculate the number of atoms in this amount of 13C? Express your answer numerically in atoms of carbon.The mole (a...

Solved • Jul 1, 2020

Mole Concept

Q. How many moles of atoms are in 4.00 g of 13C? Express your answer numerically in moles.The mole (abbreviated mol) is a counting unit used to simpli...

Solved • Jul 1, 2020

Mole Concept

Q. Lead glass contains 18-40% by mass of PbO (instead of CaO in regular glass). Lead glass is still used industrially, but lead crystal drinking goble...

Solved • Jun 30, 2020

Mole Concept

Q. (b) How many sulfur atoms are in 1.10 mol of aluminum sulfide? Express the number of atoms of S.

Solved • Jun 30, 2020

Mole Concept

Q. What units are typically used to express molar mass?

Solved • Jun 30, 2020

Mole Concept

Q. What units are typically used to express formula weight?

Solved • Jun 30, 2020

Mole Concept

Q. (a) How many sulfur atoms are in 0.45 mol BaSO4?  Express the number of atoms of S.

Solved • Jun 30, 2020

Mole Concept

Q. The world population is estimated to be approximately 7 billion people. How many moles of people are there?

Solved • Jun 30, 2020

Mole Concept

Q. Very small crystals composed of 1000 to 100,000 atoms, called quantum dots, are being investigated for use in electronic devices.. (c) The density ...

Solved • Jun 30, 2020

Mole Concept

Q. Very small crystals composed of 1000 to 100,000 atoms, called quantum dots, are being investigated for use in electronic devices. (b) How many sili...

Solved • Jun 30, 2020

Mole Concept

Q. Which of the following is the correct formula weight for calcium phosphate?a) 182.2 amub)  175.1 amuc) 278.2 amud) 310.2 amue) 135.1 amu

Solved • Jun 30, 2020

Mole Concept

Q. How is Avogadro's number referred to as a mole?

Solved • Jun 16, 2020

Mole Concept

Q. Calculate the mass of 9.33 x 1014 SO3 molecules in scientific notation

Solved • Jun 16, 2020

Mole Concept

Q. A sample of glucose C6H12O6 contain 2.0 X 1022 atoms of carbona) How many atoms of hydrogen does the sample contain?b) How many molecules of glucos...

Solved • Jun 16, 2020

Mole Concept

Q. How many argon (Ar) atoms are there in 1.5 x 102 g of argon?

Solved • Jun 16, 2020

Mole Concept

Q. You need 2.5 mol of iron (Fe) for an experiment. How many grams of iron must you measure out?

Solved • Jun 16, 2020

Mole Concept

Q. 12.-16.In a reaction of a flare, 5 grams of magnesium were reacted.12. How many moles of magnesium were reacted? (a) 0.4 (b) 0.8 (c) 1.6 (d) 0.2 (e...

Solved • Apr 30, 2020

Mole Concept

Q. Calculate the number of oxygen atoms in 29.34 g of sodium sulfate,Na2SO4.A. 1.244 × 1023 O atomsB. 4.976 × 1023 O atomsC. 2.409 × 1024 O atomsD. 2....

Solved • Apr 30, 2020

Mole Concept

Q. How many moles of chlorine atoms would be in 0.165 moles of PCI3?(a) 8.92 (b) 26.77 (c) 1.4 x 10-3 (d) 0.495 

Solved • Apr 30, 2020

Mole Concept

Q. If you had 0.165 moles of PCI3 how many grams of PCI3 would you have? (a) 2112 (b) 8.92 (c) 4.7 x 10-4 (d) 22.66 (e) none of these

Solved • Apr 30, 2020

Mole Concept

Q. If you weighed out 125 grams of PCI3 how many moles of PCI3 would you have? (a) 0.91 (b) 5.492 (c) 3.4 x 103 (d) none of these

Solved • Apr 30, 2020

Mole Concept

Q. A mole is... (a) the number of atoms in exactly 12.00 grams of C-12 (b) Avogadro's number of particles (c) 6.022 x 1023 particles (d) all of these ...

Solved • Apr 30, 2020

Mole Concept

Q. Consider the following equation: N2 + 3 H2 → 2 NH3. Which of the following statements is NOT true for this equation? (a) 1 L of N2 reacts with 3 L ...

Solved • Apr 30, 2020

Mole Concept

Q. How many molecules are in 237 g (about a cup) of water? (a) 1513.1 (b) 4267 (c) 6.02 x1023 (d) 93 x 1024 (e) 7.93 x 1024

Solved • Apr 30, 2020

Mole Concept

Q. What mass of carbon is present in 1.4 x 1020 molecules of sucrose (C12H22O11)?Molar mass of C12H22O11 = 342 g/mol

Solved • Apr 30, 2020

Mole Concept

Q. The number of hydrogen atoms in 0.050 mol of C3H8O3 is A) 3.0 x 1022 H atomB) 1.2 × 1023 H atomsC) 2.4 × 1023 H atomsD) 4.8 x 1023 H atomsE) none o...

Solved • Apr 29, 2020

Mole Concept

Q. Which sample contains the greatest number of moles of Cl?(a) 3.8 mol HCl(b) 1.7 mol CH2Cl2(c) 4.2 mol NaClO3(d) 2.2 mol Mg(ClO4)2

Solved • Apr 28, 2020

Mole Concept

Q. How many moles of oxygen are in 25.45 g of CaCO3?

Solved • Apr 28, 2020

Mole Concept

Q. Calculate the total number of:A) atoms in one molecule of trinitrotoluene (TNT), CH3C6H2(NO2)3B) atoms in 1.08 × 10+3 mol CH3(CH2)4CH2OHC) F atoms ...

Solved • Apr 27, 2020

Mole Concept

Q. What mass (in mg) does 2.63 moles of nickel have?

Solved • Apr 23, 2020

Mole Concept

Q. The world population is estimated to be approximately 7 billion people. How many moles of people are there?Express your answer using one significan...

Solved • Apr 22, 2020

Mole Concept

Q. NaOH + KHP → NaKP + H2O (formula weight of KHP =204.2)calculate number of moles of KHP that are present in 0.693 grams of KHP.calculate number of m...

Solved • Apr 21, 2020

Mole Concept

Q. How many atoms of oxygen are contained in 47.6 g of Al2(CO3)3? The molar mass of Al2(CO3)3 is 233.99 g/mol. A. 1.23 × 1023 O atoms B. 2.96 × 1024 O...

Solved • Apr 20, 2020

Mole Concept

Q. How many moles of PCl3 contain 3.68 x 1025 chlorine atoms? A. 61.1 moles PCl3 B. 20.4 moles PCl3 C. 16.4 moles PCl3 D. 54.5 moles PCl3E. 49.1 moles...

Solved • Apr 20, 2020

Mole Concept

Q. What is the formula for ammonium sulfide? How many hydrogen atoms are in 7.20 mol of ammonium sulfide?

Solved • Apr 15, 2020

Mole Concept

Q. (a) If the average mass of a single hydrogen atom is 1.67 x 10-24 g, what is the mass in grams of 6.02 x 1023 hydrogen atoms? How does your answer ...

Solved • Apr 14, 2020

Mole Concept

Q. (a) If the atomic mass of an element is x, what is the mass in grams of 6.02 x 1023 atoms of the element? (b) If 6.02 x 1023 atoms of element Y hav...

Solved • Apr 14, 2020

Mole Concept

Q. How many nitrogen atoms are in 10.2 g of copper(II) nitrate?

Solved • Apr 14, 2020

Mole Concept

Q. Part A:How many moles of atoms are in 4.00 g of 13C? Express your answer numerically in moles. Part B:Based on your answer above, can you help to c...

Solved • Apr 14, 2020

Mole Concept

Q. Using the periodic table of elements, determine the molar mass for this molecule: BaSO4SHOW YOUR WORK PLEASE

Solved • Mar 17, 2020

Mole Concept

Q. Determine the number of atoms for each element present in the following molecule: BaSO4SHOW YOUR WORK PLEASE

Solved • Mar 17, 2020

Mole Concept

Q. A raindrop has a mass of 50. mg and the Pacific Ocean has a mass of 7.08 X 1020 kg. Use this information to answer the questions below. Be sure you...

Solved • Mar 17, 2020

Mole Concept

Q. Sodium reacts with oxygen to form sodium oxide and has the following balanced chemical equation: 4 Na + O2 → 2 Na2O. How many mole(s) of oxygen gas...

Solved • Mar 12, 2020

Mole Concept

Q. Consider the heating curve shown below for 22.86 grams of an unknown substance. You may assume constant pressure conditions. Note: the points are l...

Solved • Dec 19, 2019

Mole Concept

Q. What is the mass in grams of 9.76 x 1012 atoms of sodium?A. 22.99 gB. 1.63 x 1011 gC. 3.73 x 10-10D. 1.07 x 1014 gE. 7.05 x 1023 g

Solved • Nov 28, 2019

Mole Concept

Q. For which compound does 0.256 mole weigh 12.8 g?A. C2H4OB. CO2C. CH3ClD. C2H6E. none of these

Solved • Nov 21, 2019

Mole Concept

Q. How many Br - anions are there in 3.50 g of MgBr 2?a. 3.17 x 1025 anionsb. 1.14 x 1022 anionsc. 6.34 x 1025 anionsd. 2.29 x 1022 anions

Solved • Sep 30, 2019

Mole Concept

Q. Calculate the molar mass of Ba(C 2O4)2.a. 313.37 g/molb. 328.01 g/molc. 301.90 g/mold. 128.53 g/mole. 294.77 g/mol

Solved • Sep 30, 2019

Mole Concept

Q. How many molecules of N2O4 are in 76.3 g N2O4? The molar mass of N2O4 is 92.02 g/mol.a. 5.54 x 1025 N2O4 moleculesb. 4.99 x 1023 N2O4 moleculesc. 4...

Solved • Sep 30, 2019

Mole Concept

Q. What is the molar mass of MgCl 2?A. 127.21 g mol–1      B. 75.76 g mol–1      C. 59.76 g mol–1D. 84.07 g mol–1      E. 95.21 g mol–1

Solved • Sep 18, 2019

Mole Concept

Q. How many chlorine atoms are in 1.0g of CCl4?a) 6.0 × 1023            b) 6.5 × 10-3       c) 3.9 × 1021        d) 1.6 × 1022          e) 3.9 × 1022

Solved • Sep 14, 2019

Mole Concept

Q. Identify the element from the following information. In 10.234 grams of this element, there are 1.050 x 1023 atoms.a. Hb. Scc. Nid. Hfe. Au

Solved • Sep 14, 2019

Mole Concept

Q. How many atoms are contained in 51.6 mL mercury (Hg)? The density of Hg is 13.5 g/mL.a. 1.11 x 10-2b. 3.47c. 6.68 x 1021d. 2.09 x 1024e. 8.41 x 1028

Solved • Sep 14, 2019

Mole Concept

Q. How many moles of copper are in 35.8 grams of copper (Cu)?a. 5.94 x 10-23b. 3.39 x 1023c. 0.563d. 1.78e. 2280

Solved • Sep 14, 2019

Mole Concept

Q. Assume a perfect sphere of Al has a radius of 0.700 mm. How many Al atoms are in the sphere?The density of Al is 2.70 g/cm3. Volume of a sphere = 4...

Solved • Sep 14, 2019

Mole Concept

Q. How many Zn atoms are contained in 922 g of Zn?A) 4.18 × 1024 Zn atomsB) 4.27 × 1022 Zn atomsC) 5.90 × 1025 Zn atomsD) 8.49 × 1024 Zn atomsE) 7.09 ...

Solved • Sep 12, 2019

Mole Concept

Q. What mass (in kg) does 4.77 moles of nickel have? A) 0.280 kgB) 0.632 kg C) 0.352 kg D) 0.820 kg E) 0.122 kg

Solved • Sep 12, 2019

Mole Concept

Q. How many chlorine atoms are there in 4.50 mol of aluminum chloride?

Solved • Sep 1, 2019

Mole Concept

Q. How many Fe(II) ions are there in 20.00 g of FeSO 4?

Solved • Sep 1, 2019

Mole Concept

Q. How many moles of C8H18 contain 9.25 x 1024 molecules of C8H18?

Solved • Sep 1, 2019

Mole Concept

Q. What is the mass of 0.500 mol of dichlorodifluoromethane (CCl 2F2)?

Solved • Sep 1, 2019

Mole Concept

Q. How many iron atoms are contained in 354 g of iron?

Solved • Sep 1, 2019

Mole Concept

Q. How many moles of Kr are contained in 398 mg of Kr?

Solved • Sep 1, 2019

Mole Concept

Q. A 15.5 gram sample of diphosphorus pentoxide contains how many grams of phosphorus?

Solved • Sep 1, 2019

Mole Concept

Q. How many molecules of nitrogen monoxide are in a 22.5 gram sample?

Solved • Sep 1, 2019

Mole Concept

Q. What is the mass of 1.56 x 10 26 atoms of magnesium in grams?

Solved • Sep 1, 2019

Mole Concept

Q. What is the mass of 0.560 moles of chlorine gas?

Solved • Sep 1, 2019

Mole Concept

Q. How many moles of Cu are in 1.48 x 10 25 Cu atoms?

Solved • Sep 1, 2019

Mole Concept

Q. How many atoms are in 5.80 moles of He?

Solved • Sep 1, 2019

Mole Concept

Q. If 2.01 x 1023 atoms of an element from Group IA on the periodic table has a mass of 7.675 grams, this element is most likely...

Solved • Sep 1, 2019

Mole Concept

Q. How many moles are there in 17.5 grams of sodium?

Solved • Sep 1, 2019

Mole Concept

Q. The density of acetic anhydride (C4H6O3) is 1.08 g/mL. How many moles are contained in 5mL? Please show in detail how the answer was obtained.

Solved • Aug 29, 2019

Mole Concept

Q. What is the molar mass of dinitrogen monoxide?

Solved • Aug 25, 2019

Mole Concept

Q. What is the molar mass of silver nitrate?

Solved • Aug 25, 2019

Mole Concept

Q. What is the molar mass of sodium carbonate?

Solved • Aug 25, 2019

Mole Concept

Q. What is the mass of one atom of copper in grams?

Solved • Aug 8, 2019

Mole Concept

Q. What is the molecular mass of sodium oxide  Na2O?

Solved • Aug 8, 2019

Mole Concept

Q. How many hydroxide ions are in 2.5 mol Mg(OH) 2?

Solved • Aug 8, 2019

Mole Concept

Q. What is the molecular weight of oxygen?

Solved • Aug 8, 2019

Mole Concept

Q. A sample of chlorine gas has a mass of 39.2 grams. How many  Cl2 molecules are there in the sample?

Solved • Aug 8, 2019

Mole Concept

Q. What is the number of moles of beryllium atoms in 36 g of  Be?

Solved • Aug 7, 2019

Mole Concept

Q. What is the molar mass of lithium oxide, Li2O?

Solved • Aug 7, 2019

Mole Concept

Q. What is the mass (in grams) of 9.92 x 10 24 molecules of methanol (CH3OH)?

Solved • Aug 6, 2019

Mole Concept

Q. How many atoms are in 0.920g of P2O5?

Solved • Aug 6, 2019

Mole Concept

Q. Calculate the number of atoms in a 2.93 x 10 23 g sample of silicon.

Solved • Aug 6, 2019

Mole Concept

Q. Calculate the formula mass of calcium iodite Ca(IO 2)2 in amu.

Solved • Aug 6, 2019

Mole Concept

Q. The chemical formula for t-butanol is: (CH3)3COH. Calculate the molar mass of t-butanol. Round your answer to 2 decimal places.

Solved • Aug 6, 2019

Mole Concept

Q. Calculate the formula weight of cobalt (III) carbonate, Co 2(CO3)3 in amu per formula unit, and grams per mole. Please show details.

Solved • Aug 6, 2019