A typical person has an average heart rate of 68.0 beats/min. Calculate the given questions. How many beats does she have in 4.0 years? How many beats in 4.00 years? And finally, how many beats in 4.000 years? Pay close attention to significant figures in this question.

4.0 years:_____beats

4.00 years:_____beats

4.000 years:_____beats

A new wastewater treatment plant was built to treat the wastewater flow 800,000 gpd. The capital cost to build the wastewater treatment plant was $6,000,000. The annual operation and maintenance costs of operating the plant is $700,000/year. Estimate the cost of treating 1000 gallons of wastewater ($/1000 gallon). Assume the design life as 20 years and interest rate of 4%.

A digital watch battery draws 0.40 milliamperes of current, which is provided by a mercury battery whose net reaction is: HgO(s) + Zn(s) → ZnO(s) + Hg(l) If a partially used battery contains 1.80 g of each of these four substances, for how many hours will the watch continue to run?

Calculate the ionic strength in a solution that contains 0.010 mol KCl, 0.005 mol MgCl2, 0.002 mol MgSO4, and 100g H2O.

Describe a low carbohydrate diet and a low fat diet. Be sure to describe them at the molecular level and relate them to the pathways we’ve studies in this class. Compare and contrast these two with a severe caloric deficit diet (i.e. starvation). Which of the two diets most closely resembles starvation in terms of metabolic pathways.

A very long pipe is capped at one end with a semipermeable membrane. How deep (in meters) must the pipe be immersed into the sea for fresh water to begin to pass through the membrane? Assume the water to be at 20.0°C and treat it as a 0.700 M NaCl solution. The density of seawater is 1.03 g/cm3 and the acceleration due to gravity is 9.81 m/s2.

Calculate the pH of each of the following solutions:

a. 0.00184M H+

b. 6.23 x 10-4M HCl

c. 3.18 x 10-2M NaOH

d. 4.12 x 10-4M NaOH

20. The chemical equation for the reaction between hydrochloric acid and potassium hydroxide is HCl(aq) + NaOH(aq) NaCl(aq) + H2O(l)

When 25 mL of 1.0 M HCl (36.5 g/mol) is mixed with 25 mL of 1.0 M NaOH (40 g/mol), the temperature change of the mixture is 6.9 oC. The density of the mixture is 1.00 g/mL and the specific heat of the solution is 4.18 J/ g oC. What is the enthalpy change for this reaction?

What is the mole fraction of O2 in a mixture of 15.1 g of O2, 8.19 g of N2, and 2.47 g of H2?

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Part B

Part complete

What is the mole fraction of N2 in a mixture of 15.1 g of O2, 8.19 g of N2, and 2.47 g of H2?

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Part C

Part complete

What is the mole fraction of H2 in a mixture of 15.1 g of O2, 8.19 g of N2, and 2.47 g of H2?

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What is the partial pressure in atm of O2 of this mixture if it is held in a 15.20 −L vessel at 16 ∘C?

What is the partial pressure in atm of N2 of this mixture if it is held in a 15.20 −L vessel at 16 ∘C?

What is the partial pressure in atm of H2 of this mixture if it is held in a 15.20 −L vessel at 16 ∘C?

Buffer capacity is a measure of a buffer solution\'s resistance to changes in pH as strong acid or base is added. Suppose that you have 115 mL of a buffer that is 0.340 M in both propanoic acid (C2H5COOH) and its conjugate base (C2H5COO–).

Calculate the maximum volume of 0.450 M HCl that can be added to the buffer before its buffering capacity is lost.

Carbonic acid (H2CO3) is a weak diprotic acid with Ka1=4.43×10−7 and Ka2=4.73×10−11. When sodium bicarbonate (NaHCO3) is titrated with hydrochloric acid (HCl), it acts as a weak base according to the equation

NaHCO3(aq)+HCl(aq)→H2CO3(aq)+NaCl(aq)

Part A

What volume of 0.190 M HCl is required for the complete neutralization of 1.70 g of NaHCO3 (sodium bicarbonate)?

Express your answer to three significant figures and include the appropriate units.

Part B

What volume of 0.120 M HCl is required for the complete neutralization of 1.80 g of Na2CO3 (sodium carbonate)?

Express your answer to three significant figures and include the appropriate units.

Part C

A sample of NaOH (sodium hydroxide) contains a small amount of Na2CO3 (sodium carbonate). For titration to the phenolphthalein endpoint, 0.170 g of this sample requires 23.98 mL of 0.100 M HCl. An additional 0.700 mL of 0.100 M HCl is required to reach the methyl orange endpoint. What is the percentage of Na2CO3 by mass in the sample?

Express your answer to three significant figures and include the appropriate units.