General Chemistry
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A sample of water was detected to have 0.015 mg/L of diazinon, an insecticide. Express this concentration in molarity. (Molar mass diazinon = 304.35 g/mol)
At 25.0 ºC, a 32.0% by mass HCl solution has a density of 1.161 g/mL. Express this concentration in molarity.
The concentration of dissolved iron in the Pacific Ocean is 2.0 × 10–9 g/mL. Convert this to molarity.
A solution was made by dissolving 17.0 g acetic acid (CH3CO2H) with enough water to produce 500.0 mL solution. Calculate the molarity.
Sodium hypochlorite, NaOCl, is the component of household bleach. The density of a 14.0% by mass sodium hypochlorite solution is 1.21 g/cm3 at 20 ºC. Calculate the molarity of the solution.
Which of the following is more concentrated, 0.300 M NaCl solution and 0.9% mass NaCl in water? Assume the density of the solutions is the same as water.
Calculate the mass of solid NaOH required to prepare 250.0 mL of 0.200 M NaOH solution. What glassware should be used for preparing solutions with precise volumes?
A NaCl solution has a salinity of 16.0 and a density of 1.114 g/mL. Calculate the molar concentration of Cl– ion in the solution.
White gold is an alloy made up of gold and palladium. A bar of 14-karat gold has a density of 16.5 g/cm3 and contains 58.3% gold and 41.7% palladium by mass. What is the molar concentration of gold in the solution?
Acetone (C3H6O) has a density of 0.7845 g/mL and diethyl ether ((C2H5)2O) has a density of 0.7134 g/mL. A volume of 46.5 mL of acetone is dissolved in 120.5 mL of diethyl ether. Calculate the molar concentration of acetone in the solution (assume the volumes are additive).
Calculate the molarity of a solution of 8.50 g of MgSO4•7 H2O in 300 mL of solution.
Starting with solid Ba(NO3)2, how would you prepare 2.50 L of 0.150 M aqueous solution of Ba(NO3)2?
Consider a 425 mL aqueous solution of 2.00 M H2SO4. How many moles of solute are present in the solution?
Calculate the molarity of a solution that is 13.5% NaCl by mass. Use the density of water as the density of the solution.
Calculate the molarity of a solution prepared by dissolving 80.0 g of sodium acetate with enough water to prepare a 1.75 L solution.
Consider 0.50 mol CaBr2 and 1.0 M NaBr. Can you determine which between them has more Br- ions?
A 100 proof (50% V/V) Scotch whisky is about 8.60 M ethanol (C2H5OH). Calculate the volume of ethanol needed to make a 750 mL solution that would be as strong as scotch whiskey assuming a density of 0.789 g/mL of ethanol.
Vancomycin (C22H24N2O9) is used to treat serious bacterial infections. Calculate the volume of 2.450 x10-16 M stock solution of Vancomycin needed to prepare 100 mL solution that would disable 2.50 x109 bacteria. Assume that 1 molecule of Vancomycin is needed per bacterial cell.
A chemical spill happened on a lake near a herbicide factory. It was discovered that 15,634 L of Atrazine (C8H14ClN5) contaminated the lake through a broken pipeline. Calculate the molarity of Atrazine in the lake if the density of Atrazine is 1.187 g/cm3 and the lake has a diameter of 3.00 km and an average depth of 10.00 m.
Calculate the molarity of the solution made by diluting 15.0 mL of pure H2SO4 (density=1.8302 g/cm3) to 500 mL.
Brass is made of copper and zinc of varying proportions and mechanical and electrical properties to develop different types of brass alloys. Gilding metal is typically used for ammunition bullet jackets and this has a composition of 95.0 % copper and 5.00 % zinc. Identify whether Cu or Zn is the solute in gilding metal and calculate the molarity assuming a sample of 50.0 g and density of 8.80 g/cm³.
Consider a person that drank alcohol in a bar. It was measured that they have 1.35 g total of alcohol (ethanol, C2H5OH) in their body. The average blood volume for their height is 4.5 L. The concentration of alcohol is halved every 4 hours. Calculate the concentration of alcohol in terms of molarity after 8 hours.
Blood Alcohol Content (BAC) is a measure of alcohol (ethanol, C2H6O) in the blood in grams of alcohol per 100 mL of blood. For drivers under 21, the limit can be as low as 0.02 in some states. Calculate this the BAC of 0.02 in terms of molarity.
Serotonin is a type of chemical messenger known as a neurotransmitter. It plays an important role in regulating a variety of body functions and feelings. In an experiment, rats are dosed with 1.5 mg/kg of a new drug and it showed an increase in serotonin in their brains by 0.35 mM after just 5 minutes. Calculate the molecules of serotonin produced in this amount of time if the rat's brain was measured to be 4.50 mm3.
An antibacterial agent is being developed for a newly discovered bacteria. For the experiment, 5.00 mL of 5.5 X 10-5 M antibacterial solution is used for an a bacterial colony containing 4.1 x 106 cells. Calculate the ratio of the antibacterial agent molecules to the number of bacteria cells.
Water softeners are used to replace metal ions such as Ca2+ and Mg2+ in hard water with Na+. Calculate the moles of Na+ needed to replace these ions in 5 L of hard water with 0.035 M Ca2+ and 0.011 M Mg2+
Calculate the molarity of a 70.0% (w/w) perchloric acid (HClO4) solution in water. The density of the solution is 1.67 g/mL.
Determine the volume of 2.45 M acetone that contains 56.7 moles of acetone
What is the concentration in molarity of 458 mg K2O dissolved in 50.6 mL solution ?
What is the concentration in molarity of 7.56x10-2 mol of RaF dissolved in 3.57x10-3 L solution?
Calculate the mass of MgI2 needed to prepare 0.200 L of 4.59 M MgI2 solution.
Calculate the moles of Sr3N2 in 17 L of 0.02 M Sr3N2 solution.
Calculate the mass (in grams) of Cs2SO4 needed to prepare 15 mL of a 56 M Cs2SO4 solution
An antiseptic solution is made by 2.3% antiseptic (MW = 556.94 g/mol) in water. It has a density of 0.9873 g/mL. Calculate the molarity of the antiseptic solution.
Lets say you have a solution of table salt (NaCl) dissolved in water. What would happen to the concentration of the solution as it boils? Explain your answer with a drawing.
a) decreases
b) increases
c) stays the same
d) not enough info
Which of the following solutions have the same molar concentration as Solution Y? Assume all contain the same volumes.
Calicheamicin gamma-1, C55H74IN3O21S4, is a very potent anti-tumor antibiotic. One molecule of this antibiotic can kill one bacterial cell. Find volume of an aqueous Calicheamicin gamma-1 solution that could kill 5.0 x 107 bacterial cells, from a 2.5 x 10-7 M stock solution.
A particular 0.55 M solution contains 1.7 g of salt. What mass of salt would be present in the same volume of a 3.20 M solution?
Determine volume of a 0.358 M KBr solution needed to provide 15.25 g of KBr.
A solution contains equal masses of propylene glycol (C3H8O2) and water, and has a density of 1.04 g/mL. Calculate the Molarity of this propylene glycol solution.
1.50 L sample of water extracted from the surface of the Dead Sea (which is more than 10 times saltier than ordinary seawater) and is evaporated. If 3.5 x 102 grams of MgCl2 are recovered from the seawater, what is the concentration (M) of MgCl2 in the original sample?
It takes 6.15 g of Fe(NO3)3 dissolved in water to make 300 mL of solution. Calculate the molar concentration of NO3- ions, if the molar mass of Fe(NO3)3 is 241.9 g/mol.
A chemist added 375 mL of 4.2 x 10-3 mM silver(II) oxide, AgO, solution to a flask. Determine the mass in micrograms of AgO the chemist has added to the flask. Express your answer to 2 sig figs.
A scientist is making a solution of ferric sulfide, Fe2S3, for a laboratory experiment. If a scientists needs to produce 450 mL of a solution that has a concentration of Fe+3 ions of 0.300 M, how many grams of Fe2S3 will be needed?
How many moles of NaCl are in 46.0 mL of a 0.500 M solution of NaCl?
a) 0.023 moles
b) 0.01087 moles
c) 23 moles
d) 10.9 moles
Calculate the volume (in mL) of a 4.50 M CsOH solution that will produce 0.220 mol of CsOH.
Potassium chlorate, KClO4, is an ionic compound that is very soluble in water. About 25.0 g of potassium chlorate was dissolved in 650 mL of water. Calculate the molarity of the solution.
A concentration of potassium ions below 2.5×10–3 M in the blood can already be life-threatening. If the blood volume is 5.0 L, calculate the mass of potassium chloride needed to increase the potassium ions from 2.5×10–3 M to a safe level of 4.5×10–3 M. Assume there is no change in blood volume.
How many liters of a 0.250 M acetonitrile solution will contain 1.4×10−3 mol acetonitrile?
Calculate the normality and the equivalent mass of 4.2 x 10-3 M H2SO4 acid solution.
What is the molarity of Br− in each solution? 0.175 M NaBr