For each of the following unbalanced reactions, suppose 5.18 g of each reactant is taken. Determine which reactant is limiting, and also determine what mass of the excess reagent(s) will remain after the limiting reactant is consumed. Na2B4O7(s) + H2SO4(aq) + H2O(l) → H3BO3(s) + Na2SO4(aq)

Complete the following table by calculating the missing entries and indicating whether the solution is acidic, basic or neutral. the pOH for one row is 9.75 and the H+ on the bottom row is 6.17x10^-11.

For the row that the pOH is 9.75 you have to find the pH, the H+, OH- and if its an acid or base. For the row that the H+ is 6.17 x 10^-11 you have to find the ph, pOH, OH- and if its an acid or base

Find the pH during the titration of 20.00 mL of 0.2830 M benzoic acid, C₆H₅COOH (K_a = 6.3 ✕ 10^-5), with 0.2830 M NaOH solution after the following additions of titrant.

(a)    0 mL


(b)    10.00 mL


(c)    15.00 mL


(d)    19.00 mL


(e)    19.95 mL


(f)    20.00 mL


(g)    20.05 mL


(h)    25.00 mL

A dryer is operated with a material containing 10% H2O (by mass) to a final dried material containing 5% H2O (by mass). The fresh air is mixed with recycled air and is blown over the solid. The fresh air contains 0.008 kg H2O/kg dry air and the recycled air contains 0.08 kg H2O/kg dry air. For 1000 kg of wet material fed to the dryer. Calculate (a) weight of H2O removed, (b) weight of dry air in the fresh air feed and (c) weight of dry air recycled.

Consider the following reaction:  2 A + 3 B2 ⇌ A2B6

The initial concentrations of A and B2 are 0.245 M and 0.730 M, respectively, with no A2B6 initially present. When the reaction comes to equilibrium, the concentration of A2B6 is found to be 9.50×10−2 M.

Part A

What is the equilibrium concentration of A?

Round your answer to 3 significant figures.

Part B

What is the equilibrium concentration of B₂?

Round your answer to 3 significant figures.

Part C

What is the value of the equilibrium constant?

Round you answer to 3 significant figures.

Problem: Two primary batteries are based on the cell reactions as follows:

2 MnO₂ + Zn + 2NH₄Cl -> Mn₂O₃ + Zn(NH₃)₂Cl₂ + H₂O

and

2Li + 2SO₂ -> Li₂S₂O₄

that have free energies of -229 Kj/mol of Zn and -294 Kj/mol of Li, respectively. Typical batteries have a capacity of 2 Ah (ampere hours). Estimate the battery voltages and the weights of the two metals needed to deliver this capacity. Do your calculations reveal any advantages for Li battery? (Atomic weights of Zn and Li are 65 and 7, respectively.)

A mixture is made by combining 19.9 mL of 1.2×10−3 M KSCN, 8.5 mL of 8.1×10−2 M Fe(NO3)3, and 11 mL of 0.198 M HNO3. Calculate the concentration of Fe3+ in the solution.

what the ph of 0.109 M hydrogen chromate ion (HCrO4^-)

The concentration of grain alcohol (C₂H₅OH) in whisky is given in "degrees proof", which is twice the percent alcohol by volume (v/v). What are the mole fraction and molality of C₂H₅OH in 80.

One way of achieving an IPSP is to increase permeability to Cl^-. By what other mechanism can you achieve an IPSP (change permeability to what ion)? Explain why.

PLEASE answer this question COMPLETELY and I'll be sure to give you five star feedback!

Just answers.

A. A buffer solution that is 0.431 M in HClO and 0.431 M in NaClO has a pH of 7.46.

(1) The addition of 0.01 mol of H₃O⁺ to 1.0 L of this buffer would cause the pH to _________(increase slightly, increase by 2 units,decrease slightly,decrease by 2 units,not change.)

(2) The capacity of this buffer for added OH^- could be increased by the addition of 0.147 mol  _________(of the weak acid,of the salt.)

B. How many grams of solid sodium fluoride should be added to 2.00 L of a 5.23×10^-2M hydrofluoric acid solution to prepare a buffer with a pH of 3.816 ?

grams sodium fluoride =  g.

C.How many grams of solid ammonium bromide should be added to 2.00 L of a 0.287 M ammonia solution to prepare a buffer with a pH of 8.740 ?  

grams ammonium bromide =

chem lab: Solvent Free Wittig Reaction Lab

Wittig reaction= reaction of a phosphonium ylide with an adehyde or ketone to make a new alkene

A.) Another isomer of the product is formed to a small extent. Draw the structure. Why might we expect this product to be formed in only small amounts?

B.) Give a sequence of reactions showing how the ylide used in the lab could be synthesized from triphenylphosphine

A 75.0-mL sample of 0.0500 M HCN (Ka = 6.2e-10) is titrated with 0.212 M NaOH. What is the [H+] on the solution after 3.0 mL of 0.212 M NaOH have been added?

I know the answer is 3.0 x 10^-9 M but I am not sure about the steps please help

what would happen to the values you calculated for kc in the experiment if the beer's law constant (k) value you used was high (e.g.you used 6000 M^-1 when the actual constant had a value of 5000 M^-1) ? Explain your answer.

how do each of the following affect the calculated volume of hydrogen gas at stp?

A: The strip of magnesium used in the experiment was partly oxidized and it was not cleaned before the strip was bent and placed in the buret.

B: The bent strip of magnesium dropped out of the end of the buret and some bubbles of H2 from the reaction were not trapped in the buret.

C: you did not correct the bariometric pressure for the vapor pressure of water.