Question 1

Concentrated sulfuric acid contains 4 g of water for every 100 g of solution. The solvent is __________

Accepted Answer

In a solution, the solvent is the component present in the greatest amount. Since the solution is described as "concentrated sulfuric acid" with only 4 g of water per 100 g of solution, the majority of the solution is sulfuric acid, making it the solvent.

Question 2

Molarity, M, is defined as __________

Accepted Answer

Molarity is defined as the number of moles of solute dissolved in one liter of solution, not just the solvent.

Question 3

How many grams of solid magnesium chloride, MgCl₂, are needed to make 250 mL of 0.50 M solution?

Accepted Answer

To calculate the amount (in grams) of magnesium chloride needed, we can use the formula:

mass = molarity x volume x molar mass

where molarity is given as 0.50 M, volume is 250 mL, and molar mass of MgCl2 is (24.31 + 2x35.45) = 95.21 g/mol.

Substituting the values, we get:

mass = 0.50 x 0.25 x 95.21 
mass = 11.90 g

Therefore, we need 11.90 g of magnesium chloride. However, since the answer choices only have one option in grams, we choose the one closest to 11.90 g, which is option C (12 g).

Question 4

Lead is the least toxic to fish compared to zinc, copper, and mercury ions. Fish can tolerate a lead concentration slightly above 0.850 mM. What is this concentration in ppm? Assume the density of the water is 1.00 g/mL.

Accepted Answer

To convert mM to ppm, use the formula: ppm = (mM) * (molar mass of lead in g/mol). The molar mass of lead (Pb) is approximately 207.2 g/mol. Thus, 0.850 mM * 207.2 g/mol = 176.12 ppm, which rounds to 176 ppm.

Question 5

If 120 g of NaOH were used to prepare 500 mL of solution, what would the concentration be?

Accepted Answer

The answer of If 120 g of NaOH were used...

Question 6

A medical saline solution is prepared by mixing 925 mg sodium chloride (58.44 g/mol) with water to make 100.0 mL solution. What is the molar concentration of this solution?

Accepted Answer

1. Calculate the number of moles of sodium chloride:

925 mg ÷ 58.44 g/mol = 0.0158 mol

2. Calculate the volume of the solution in liters:

100.0 mL ÷ 1000 mL/L = 0.100 L

3. Calculate the molarity of the solution:

Molarity = moles ÷ volume 
Molarity = 0.0158 mol ÷ 0.100 L = 0.158 M

Question 7

Sodium fluoride (NaF) is added to drinking water in some municipalities to protect teeth against cavities. The idea is to convert hydroxyapatite, Ca₁₀(PO₄)₆(OH)₂, into more stable fluorapatite, Ca₁₀(PO₄)₆F₂. The molar mass of hydroxyapatite is 502 g/mol. What is the molarity of a 10.0 mg/L sodium fluoride solution?

Accepted Answer

The molarity of a solution is defined as the number of moles of solute per liter of solution. To calculate the molarity of a sodium fluoride solution, we need to know the number of moles of sodium fluoride in 1 liter of solution.To do this, we can use the following formula:Molarity = (Mass of solute in grams) / (Molar mass of solute in grams/mol) x (Volume of solution in liters)In this case, we have 10.0 mg of sodium fluoride in 1 liter of solution. The molar mass of sodium fluoride is 41.99 g/mol.So, the molarity of the solution is:Molarity = (10.0 mg / 1000) / (41.99 g/mol) x (1 L) = 2.38 * 10^-4 MTherefore, the correct answer is A.

Question 8

What are the units of molar concentration, M ?

Accepted Answer

Molar concentration, or molarity, is defined as the number of moles of solute per liter of solution. Therefore, the units are mol/L.

Question 9

The amount of blood in the human body is around 5.0 L, and this amount of blood contains about 0.88 g of potassium ions. What is the concentration of potassium ions in blood?

Accepted Answer

To find the concentration of potassium ions in blood, we need to use the formula: 
Concentration (in mM) = (amount of substance in grams / molar mass in g/mol) / volume in L

The molar mass of potassium is 39.1 g/mol.

Concentration = (0.88 g / 39.1 g/mol) / 5.0 L = 0.0045 mol/L = 4.5 mM

Therefore, the correct answer is D, 4.5 mM.

Question 10

A homogeneous mixture of two or more substances is called __________

Accepted Answer

A homogeneous mixture of two or more substances is called a solution. A compound is a substance made up of two or more elements chemically bonded together. An electrolyte is a substance that conducts electricity when dissolved in water. A solvent is a substance that dissolves other substances to form a solution. "A mess" is not a scientific term and is not a proper answer.

Question 11

If there are 0.505 g of NaCl left in a beaker that originally contained 75.0 mL of saltwater, what must have been the concentration of the original solution?

Accepted Answer

The answer of If there are 0.505 g of NaCl...

Question 12

Determine the molar concentration of an aqueous solution of lead(II) nitrate solution that is 26 ppb (parts per billion) Pb(NO₃)₂. Since the solution is very dilute, assume the density is that of water, 1.00 g/mL.

Accepted Answer

The correct answer is D because 26 ppb Pb(NO3)2 is equivalent to 7.85 * 10^-8 M Pb(NO3)2.

Question 13

A chemistry student attempted to make a 0.2000 M solution of NaCl using a 100.0 mL volumetric flask. She added exactly 100.0 mL of water to the flask, then added 0.02000 mol of NaCl, and found that the total volume in the flask was above the 100.0 mL mark. What was the concentration of the solution?

Accepted Answer

Adding the 0.02000 mol of NaCl to 100.0 mL of water will result in a total volume slightly greater than 100.0 mL due to the slight increase in volume caused by the dissolution of the solute. Therefore, the final concentration of NaCl will be slightly less than 0.2000 M.

Question 14

The proof of liquor is defined as the percentage of ethanol it contains times two. If vodka is 80 proof, what is the solvent in vodka?

Accepted Answer

The solvent in vodka is water, as vodka is a mixture of ethanol and water, with water being the component present in the greater amount.

Question 15

Determine the molar concentration of ethanol (C₂H₆O) in a wine that is 14% ethanol by mass. The density of this wine is 0.93 g/cm³.

Accepted Answer

The answer of Determine the molar concentration of ethanol (C₂H₆O)...

Question 16

Human blood contains about 0.18 g potassium ions per liter and has a density of 1.06 g/mL. What is the concentration of potassium ions in blood expressed in parts per million?

Accepted Answer

The answer of Human blood contains about 0.18 g potassium...

Question 17

Which one of the following mixtures is not a solution?

Accepted Answer

A solution is a homogeneous mixture where the solute is completely dissolved in the solvent, making it uniform throughout. Pulpy orange juice is not a solution because it contains solid particles of pulp that are not dissolved, making it a heterogeneous mixture.

Question 18

A concentrated aqueous ammonia solution has a density of 0.90 g/mL and is 28.0% by mass ammonia. Determine the molar concentration of this solution.

Accepted Answer

To find the molar concentration, first calculate the mass of ammonia in 1 L of solution: 0.90 g/mL x 1000 mL = 900 g of solution. 28% of this is ammonia, so 0.28 x 900 g = 252 g of NH3. The molar mass of NH3 is 17.03 g/mol, so 252 g / 17.03 g/mol = 14.8 mol, which is approximately 15 M.

Question 19

Lead is the least toxic to fish compared to zinc, copper, and mercury ions. Fish can tolerate a concentration slightly above 0.85 mM. What is the lead concentration in mg/L?

Accepted Answer

The molar mass of lead (Pb) is approximately 207.2 g/mol. To convert 0.85 mM to mg/L, multiply 0.85 mmol/L by 207.2 mg/mmol, resulting in approximately 176.12 mg/L, which is closest to 180 mg/L.

Question 20

The National Primary Drinking Water Regulations limit the concentration of lead in drinking water to 0.015 mg/L, which is __________.

Accepted Answer

The correct conversion for 0.015 mg/L to parts per billion (ppb) is 15 ppb, since 1 mg/L is equivalent to 1000 ppb.

Quiz 4: Solution Chemistry: The Hydrosphere

Concentrated sulfuric acid contains 4 g of water for every 100 g of solution. The solvent is __________

Molarity, M, is defined as __________

How many grams of solid magnesium chloride, MgCl₂, are needed to make 250 mL of 0.50 M solution?

Lead is the least toxic to fish compared to zinc, copper, and mercury ions. Fish can tolerate a lead concentration slightly above 0.850 mM. What is this concentration in ppm? Assume the density of the water is 1.00 g/mL.

If 120 g of NaOH were used to prepare 500 mL of solution, what would the concentration be?

A medical saline solution is prepared by mixing 925 mg sodium chloride (58.44 g/mol) with water to make 100.0 mL solution. What is the molar concentration of this solution?

What are the units of molar concentration, M ?

The amount of blood in the human body is around 5.0 L, and this amount of blood contains about 0.88 g of potassium ions. What is the concentration of potassium ions in blood?

A homogeneous mixture of two or more substances is called __________

If there are 0.505 g of NaCl left in a beaker that originally contained 75.0 mL of saltwater, what must have been the concentration of the original solution?

Determine the molar concentration of an aqueous solution of lead(II) nitrate solution that is 26 ppb (parts per billion) Pb(NO₃) ₂. Since the solution is very dilute, assume the density is that of water, 1.00 g/mL.

A chemistry student attempted to make a 0.2000 M solution of NaCl using a 100.0 mL volumetric flask. She added exactly 100.0 mL of water to the flask, then added 0.02000 mol of NaCl, and found that the total volume in the flask was above the 100.0 mL mark. What was the concentration of the solution?

The proof of liquor is defined as the percentage of ethanol it contains times two. If vodka is 80 proof, what is the solvent in vodka?

Determine the molar concentration of ethanol (C₂H₆O) in a wine that is 14% ethanol by mass. The density of this wine is 0.93 g/cm³.

Human blood contains about 0.18 g potassium ions per liter and has a density of 1.06 g/mL. What is the concentration of potassium ions in blood expressed in parts per million?

Which one of the following mixtures is not a solution?

A concentrated aqueous ammonia solution has a density of 0.90 g/mL and is 28.0% by mass ammonia. Determine the molar concentration of this solution.

Lead is the least toxic to fish compared to zinc, copper, and mercury ions. Fish can tolerate a concentration slightly above 0.85 mM. What is the lead concentration in mg/L?

The National Primary Drinking Water Regulations limit the concentration of lead in drinking water to 0.015 mg/L, which is __________.

Quiz 4: Solution Chemistry: The Hydrosphere

Concentrated sulfuric acid contains 4 g of water for every 100 g of solution. The solvent is __________

Molarity, M, is defined as __________

How many grams of solid magnesium chloride, MgCl2, are needed to make 250 mL of 0.50 M solution?

Lead is the least toxic to fish compared to zinc, copper, and mercury ions. Fish can tolerate a lead concentration slightly above 0.850 mM. What is this concentration in ppm? Assume the density of the water is 1.00 g/mL.

If 120 g of NaOH were used to prepare 500 mL of solution, what would the concentration be?

A medical saline solution is prepared by mixing 925 mg sodium chloride (58.44 g/mol) with water to make 100.0 mL solution. What is the molar concentration of this solution?

What are the units of molar concentration, M ?

The amount of blood in the human body is around 5.0 L, and this amount of blood contains about 0.88 g of potassium ions. What is the concentration of potassium ions in blood?

A homogeneous mixture of two or more substances is called __________

If there are 0.505 g of NaCl left in a beaker that originally contained 75.0 mL of saltwater, what must have been the concentration of the original solution?

Determine the molar concentration of an aqueous solution of lead(II) nitrate solution that is 26 ppb (parts per billion) Pb(NO3) 2. Since the solution is very dilute, assume the density is that of water, 1.00 g/mL.

The proof of liquor is defined as the percentage of ethanol it contains times two. If vodka is 80 proof, what is the solvent in vodka?

Determine the molar concentration of ethanol (C2H6O) in a wine that is 14% ethanol by mass. The density of this wine is 0.93 g/cm3.

Human blood contains about 0.18 g potassium ions per liter and has a density of 1.06 g/mL. What is the concentration of potassium ions in blood expressed in parts per million?

Which one of the following mixtures is not a solution?

A concentrated aqueous ammonia solution has a density of 0.90 g/mL and is 28.0% by mass ammonia. Determine the molar concentration of this solution.

Lead is the least toxic to fish compared to zinc, copper, and mercury ions. Fish can tolerate a concentration slightly above 0.85 mM. What is the lead concentration in mg/L?

The National Primary Drinking Water Regulations limit the concentration of lead in drinking water to 0.015 mg/L, which is __________.

How many grams of solid magnesium chloride, MgCl₂, are needed to make 250 mL of 0.50 M solution?

Determine the molar concentration of an aqueous solution of lead(II) nitrate solution that is 26 ppb (parts per billion) Pb(NO₃) ₂. Since the solution is very dilute, assume the density is that of water, 1.00 g/mL.

Determine the molar concentration of ethanol (C₂H₆O) in a wine that is 14% ethanol by mass. The density of this wine is 0.93 g/cm³.