Chemistry 2 Lab question!

How is sulfate ion seperated from NO3 - and Cl - ?

What is precipitation hardening? Is this a kinetics or thermodynamic process? Explain.

Part A

The activation energy of a certain reaction is 39.4kJ/mol . At 30 ?C , the rate constant is 0.0190s?1. At what temperature in degrees Celsius would this reaction go twice as fast?

Express your answer with the appropriate units.

Part B

Given that the initial rate constant is 0.0190s?1 at an initial temperature of 30 ?C , what would the rate constant be at a temperature of 150 ?C for the same reaction described in Part A?

Express your answer with the appropriate units.

A "silver" ring was purchased at a local store. It was stamped "sterling silver" which means that it must contain 92.5% by mass Ag. The remaining 7.5% may technically be any other metal. Copper is typically used for this. This ring was found to be magnetic, which suggests that the non silver part may contain iron or nickel as well. A small amount of the ring is dissolved in nitric acid, making a solution of the nitrate of any metal that would be present.

a. What group does each of the four metals belong to?

b. After the removal of the silver as the insoluble chloride, the solution is made basic with 6M NH4OH. If the solution turns Violet, with no blue color present, what cation was present in the solution?

c. What would the cation present be if the solution turned a very strong navy blue color instead, when the amonium hydroxide was added?

how many moles and numbers of ions each type,are present Iin the following aqueous solution? 51.5 ml of 1.55 M magnesium chlorides

how many grams of NaOH must be added to 1L of a 0.1 M KH2PO4 to prepare a pH 7.42 buffer. answer given by professor is 2.47 I need help understanding how to solve

a.

b. Match the following aqueous solutions with the appropriate letter from the column on the right.

whic of these interactions can be explained by hydrogen bonding.

Select all that apply.

a. An aqueous solution is made by dissolving 18.4 grams of iron(III) bromide in 314 grams of water.  

The molality of iron(III) bromide in the solution is ________m.

b.In the laboratory you are asked to make a 0.473 m chromium(II) acetate solution using 425 grams of water.  

How many grams of chromium(II) acetate should you add?  
_________ grams.

c. The boiling point of diethyl ether CH₃CH₂OCH₂CH₃ is 34.50°C at 1 atmosphere. A nonvolatile, nonelectrolyte that dissolves in diethyl ether is chlorophyll.

If 10.38 grams of chlorophyll, C₅₅H₇₂MgN₄O₅ (893.5 g/mol), are dissolved in 236.2 grams of diethyl ether.

The molality of the solution is ______ m.

The boiling point of the solution is______ °C.

d. The freezing point of benzene C₆H₆ is 5.50°C at 1 atmosphere. A nonvolatile, nonelectrolyte that dissolves in benzene is DDT .  

If 14.38 grams of DDT, C₁₄H₉Cl₅ (354.5 g/mol), are dissolved in 276.5 grams of benzene ...

The molality of the solution is _____ m.

The freezing point of the solution is _________°C.

Consider the titration of 35.0 mL of 0.260 M HF with 0.215 MNaOH. Calculate the pH at each of the following points.

Part A.)

How many milliliters of base are required to reach the equivalence point?

Express your answer using three significant figures.

Part B.)

Calculate the pH after the addition of 8.75 mL of base

Express your answer using two decimal places.

Part C.)

Calculate the pH at halfway to the equivalence point.

Express your answer using two decimal places.

Part D.)

Calculate the pH at the equivalence point.

Express your answer using two decimal places.

Part E.)

Calculate the pH after the addition of 70.0 mL of base.

Express your answer using two decimal places.

1. Where do the typical IR absorption come for the following functional groups.

            Alcohol

            Alkyl

            Alkene

            Alkyne

            Aromatics

            Carboxylic acids

2.

Where do the typical IR absorption comes for amines?

Primary amines

Secondary amines

Tertiary amines

The chief compound in marble is CaCO3. Marble has been widely used for statues and ornamental work on buildings, including such structures as the Taj Mahal (Figure 1) . However, marble is readily attacked by acids via the following reaction. CaCO3(s)+H+(aq)⇌Ca2+(aq)+HCO3−(aq) Equilibrium constants at 25 ∘C are listed in the table below.

CaCO3 Ksp =4.5×10−9

H2CO3 Ka1 =4.3×10−7

H2CO3 Ka2 =5.6×10−11

Part A What is the molar solubility of marble (i.e., [Ca2+] in a saturated solution) in normal rainwater, for which pH=5.60?

A well mixed 10m³ closed mixing tank at 18C is used to dilute 100kg/min of a 2.0% by mass NaClO₃ solution to a 0.60% solution by adding water.

Part 1) What is the mass flowrate of water into the tank needed at steady-state to accomplish this dilution?

Part 2) You notice that some gas bubbles appear in the effluent, and after some additional literature reading, hypothesize that NaCl₃ is decomposing to NaCl and O₂ inside the tank because of impurities in its walls. You do not have an oxygen detector handy and so decide to build a 0.5m³ chamber above the tank to collect all the gas generated. Initially the pressure (absolute) in this collection chamber is 760mmHg. After five minutes you measure the pressure to be 1320mmHg.

a) if your hypothesis is correct, what is the mass rate of oxygen generation?

b) assuming that the NaCl₃ solution flowing in and the NaCl₃/NaCl solution flowing out each have a density of 1.0g/mL (which will be within 1% of truth), what is the concentration (g/L) of NaCl in the effluent?

c) if a portion of water from the effluent were evaporated without any additional decomposition occuring, what would be the purity of the NaClO₃?

d) after more literature reading, you believe that the rate of  NaClO₃ decomposition is directly proportional to the molar concentration of  NaClO₃ in the tank and the tank volume, Based on this hypothesis, determine the value of the proportionality constant, thereby obtaining a general expression for the rate of  NaClO₃ decomposition.

Part 3) The dilution water has been flowing and the  NaClO₃ decomposing at steady state rate. suddenly, the valve controlling the flow of dilution water malfunctions and closes, halting its flow. assuming the densities of all the solutions are approximately the same, how much time passes before the concentration of  NaClO₃ in the effluent exceeds 1%?

Please answer as soon as possible (Chemical Engineering)

Given The reactions

C₃H₈ → C₃H₆ + H₂

C₃H₈ + 2H₂ → 3CH₄

The feed contains 90.0 mole% propane(C₃H₈) and the balance inert. The fractional conversion of propane is 0.603 and the fractional yield of propylene is 0.541.

Calculate the molar composition of the product gases and selectivity of ethylene to methane production.

Explain why the addition of a small amount of base to an acidic buffer solution causes only a small change in the pH of the buffer solution. You should use any appropriate chemical and/or mathematical equations to substantiate your arguments