Imagine that you are in chemistry lab and need to make 1.00 L of a solution with a pH of 2.50.

You have in front of you

100 mL of 7.00×10⁻²M HCl,

100 mL of 5.00×10⁻²M NaOH, and

plenty of distilled water.

You start to add HCl to a beaker of water when someone asks you a question. When you return to your dilution, you accidentally grab the wrong cylinder and add some NaOH. Once you realize your error, you assess the situation. You have 81.0 mL of HCl and 90.0 mL of NaOH left in their original containers.

Assuming the final solution will be diluted to 1.00 L , how much more HCl should you add to achieve the desired pH?

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

1.) What other D aldohexose gives the same alditol as D-talose?

2.) A. The aldaric acid of D-talose is the same as the aldaric acid of which sugar? (Choices: L-allose, D-altrose, L-galactose, L-glucose, L-gulose, D-idose, D-mannose, D-talose.)

B. The aldaric acid of L-altrose is the same as the aldaric acid of which sugar?

3.) A. Which aldopentose gives the same aldaric acid as D-ribose? (Choices: D-ribose, D-arabinose, D-xylose, D-lyxose, L-ribose, L-arabinose, L-xylose, L-lyxose)

B. Which aldopentose gives the same aldaric acid as D-arabinose?

Determine the molar solubility (S) of Ag2CO3 in a buffered solution with a pH of 3.255 using the systematic treatment of equilibrium. Ksp(Ag2CO3) = 8.46 × 10–12; Ka1(H2CO3) = 4.45 × 10–7; Ka2(H2CO3) = 4.69 × 10–11.

Show all the work please. And if you're not sure, please just don't do it.

thank you

A water initially contains 50mg/L of Mg2+. The pH of the water is increased until the concentration of hydroxide ion is 0.0005 M. Calculate the concentration (mg/L) of magnesium ion in this water at this pH. Assume that the temperature of the solution is 25 degrees C.

Silver ion, Ag+, can be recovered from photographic solutions by adsorbing onto an ion exchange resin (Langmuir adsorption)

Ag+ +Ex↔ Ag-Ex logKL =12.30

(where Ex represents an adsorbing site on the resin). According to the manufacturer, the resin has 1.20 x10-5 moles of adsorbing sites per gram of resin.

a) If you have a liter of solution with [Ag+] = 0.030 mM, how much resin will you need to adsorb all the silver assuming 100% binding?

b) Calculate the predicted equilibrium dissolved [Ag+] if you add 10.00 g of resin to 1.00 liter of solution described in part a.

The ideal gas law PV=nRT relates pressure P, volume V, temperature T, and number of moles of a gas, n. The gas constant R equals 0.08206 L⋅atm/(K⋅mol) or 8.3145 J/(K⋅mol). The equation can be rearranged as follows to solve for n: n=PVRT This equation is useful when dealing with gaseous reactions because stoichiometric calculations involve mole ratios.

Part A

When heated, calcium carbonate decomposes to yield calcium oxide and carbon dioxide gas via the reaction CaCO3(s)→CaO(s)+CO2(g) What is the mass of calcium carbonate needed to produce 53.0 L of carbon dioxide at STP? Express your answer with the appropriate units.

Part B

Butane, C4H10, is a component of natural gas that is used as fuel for cigarette lighters. The balanced equation of the complete combustion of butane is 2C4H10(g)+13O2(g)→8CO2(g)+10H2O(l) At 1.00 atm and 23 ∘C, what is the volume of carbon dioxide formed by the combustion of 3.80 g of butane? Express your answer with the appropriate units.

Calcium hydride, CaH2, reacts with water to form hydrogen gas: CaH2(s)+2H2O(l)→Ca(OH)2(aq)+2H2(g) This reaction is sometimes used to inflate life rafts, weather balloons, and the like, where a simple, compact means of generating H2 is desired.

Part A

How many grams of CaH2 are needed to generate 146 L of H2 gas if the pressure of H2 is 824 torr at 22 ∘C?

The metabolic oxidation of glucose, C6H12O6, in our bodies produces CO2, which is expelled from our lungs as a gas: C6H12O6(aq)+6O2(g)→6CO2(g)+6H2O(l)

Part A

Calculate the volume of dry CO2 produced at body temperature (37 ∘C) and 0.990 atm when 23.5 g of glucose is consumed in this reaction

Part B

Calculate the volume of oxygen you would need, at 1.00 atm and 298 K, to completely oxidize 53 g of glucose.

An organic compound contains C, H, N, and O. Combustion of 0.3069 g of the compound produces 0.8301 g CO2 and 0.2975 g H2O. A sample of 0.5322 g of the compound was analyzed for nitrogen. At STP, 30.54 mL of dry N2 (g) was obtained. In a third experiment, the density of the compound as a gas was found to be 3.68 g/L at 143 deg C and 244 torr. Calculate the empirical formula and the molecular formula of the compound.

calcium in powdered milk is determined by ashing a 1.50g sample and then titrating the calcium with EDTA soluton, 12.1mL being required. The EDTA was standardized by titrating 10.0mL of a zinc solution prepared by dissolving 0.632g zinc metal in acid and diluting to 1L (10.8mL EDTA required for titration). What is the concentration of calcium in the powdered milk in parts per million?

An organic compound contains C, H, N, and O. Combustion of 0.3069 g of the compound produces 0.8301 g CO2 and 0.2975 g H2O. A sample of 0.5322 g of the compound was analyzed for nitrogen. At STP, 30.54 mL of dry N2 (g) was obtained. In a third experiment, the density of the compound as a gas was found to be 3.68 g/L at 143 deg C and 244 torr. Calculate the empirical formula and the molecular formula of the compound.

What is the pH of 0.213 M NaF(aq)?

HF: Ka = 7.2 * 10-4

Answer is 8.24

Rank the polarity of the following compounds: ferrocenecarboxylic acid, acetylferrocene, ferrocenecarboxaldehyde, ferrocene, (dimethylaminomethyl) ferrocene, and ferrocenemethanol and give a detailed explanation why.

A 50/50 blend of engine coolant and water (by volume) is usually used in an automobile\'s engine cooling system. If your car\'s cooling system holds 5.60 gallons, what is the boiling point of the solution? Make the following assumptions in your calculation: at normal filling conditions, the densities of engine coolant and water are 1.11 g/mL and 0.998 g/mL respectively. Assume that the engine coolant is pure ethylene glycol (HOCH2CH2OH), which is non-ionizing and non-volatile, and that the pressure remains constant at 1.00 atm. Also, you\'ll need to look up the boiling-point elevation constant for water.

Engineers in Brazil do not have to worry as much about the CLOUD POINT or the POUR POINT of their biodiesel as Canadian engineers do. Define these terms and suggest two ways problems relating to them can be addressed.

Experiment 1: Determining the Chemical Formula for Copper Gluconate The experiments in this lab use a compound named copper gluconate. This compound can be formed when gluconic acid (C6H12O7) and copper solutions react with copper (II) carbonates or copper hydroxide. Copper gluconate has a variety of uses and applications. For example, copper gluconate is used as a primary ingredient in the breath mint Certs®. It is also used as a source of copper in nutritional supplements. Your task will be to determine the chemical formula of the compound by isolating the copper and determining the molar ratio of copper and gluconate in the compound. Figure 3: Certs® Figure 3: Certs® Materials: 1 g Copper gluconate 10 mL 0.5% Salt, NaCl 10 mL Graduated cylinder Scale (1) 50 mL Beaker 250 mL Glass beaker 2 Aluminum washers Sterno® Ring stand Ring for ring stand Stir rod Matches Cupcake wrapper *Oven *Hot pad or towel *Baking pan *20 mL Distilled Water *Kitchen tongs *You must provide Procedure Put the 250 mL beaker on the scale and tare the scale. Measure 1.0 g of the copper gluconate in the beaker on the scale. Record the exact mass in the Data section below. Use the graduated cylinder to measure and pour 10 mL 0.5% NaCl into the beaker with the copper gluconate. You may need to gently swirl the solution if all the copper gluconate does not immediately suspend into the solution. Add two aluminum washers to the solution. Fasten the small ring approximately 6 - 10 inches up on the ring stand and place the beaker on the ring Place the Sterno® directly beneath the beaker. Remove the inner cap on the Sterno® and ignite the inner contents with the matches. Heat the beaker until solution clears. Your solution may not turn completely clear, but some color change should be evident. Alternatively you can also determine when the reaction is complete by looking for the formation of gas bubbles on the surface of the washers. When the formed gas bubbles are gone, then the reaction is complete. Note: Carefully monitor the set-up while the Sterno® is in use. You may need to adjust the height of the ring/beaker to ensure that the beaker is heated enough; and, to avoid exposing the beaker from high temperatures. **Carefully observe the set-up you choose!! Do not leave the beaker unattended while exposed to the Sterno®. Plastic beakers should never be used with heat.** Carefully remove the beaker from heat, and use forceps to replace the lid on the Sterno®. Decant (pour) the clear liquid into a 50 mL beaker. When all that remains in the original beaker are the copper plated washers, rinse the washers with distilled water and decant the remaining liquid, being careful not to lose any copper, into a container. This water can be disposed of down a sink drain. Repeat this process three times. Remove the first washer and use the stir stick to scrape the copper into the metal cupcake wrapper. Rinse the washer with distilled water to be sure all copper is recovered into the wrapper. Repeat the process for the second washer, scraping the copper into the same wrapper. Place the wrapper on a baking pan and put it in the oven at 115 °C (239 °C) to dry the product. Monitor the wrapper and contents and use a hot pad or towel to carefully remove them from the oven after 45 minutes, or after all of the water has evaporated. After the wrapper has cooled to room temperature, empty the dried copper from the wrapper onto the scale and weigh the final mass.

Why is it important in this experiment to be accurate in all your measurements?

List the measurements you will take in this experiment.

What chemical wastes are produced in this reaction?

Record the mass in the Data section below.

Data: Mass of copper gluconate (initial, see Step 2): _____________________

Mass of copper (final; see Step 13): _____________________

Calculations Mass of copper recovered:

Moles of copper :

Mass of gluconate:

Moles of gluconate:

Chemical formula:

1. What is the chemical formula of copper gluconate?

2. List two sources of error in the experiment and explain the impact they had on the results.

3. Create a pie chart showing the percent composition for each element in the compound copper gluconate, clearly label each element and the percentage.

4. Copper chloride can be used as a source of copper for this experiment, but copper gluconate is preferred due the fact that it is a “green” compound. Discuss the environmental