A 37.00 mL solution of 0.390 M weak acid Ha(aq) (Ka=2.25x10^-5) is titrate with 0.390 M NaOH(aq). Calculate the pH of the solution 14.00 mL past the end point.

1. Find the number of moles that are in 2.93g of LiO2 and report it with the correct number of significant figures
a. 8.75 x 10^22 mol
b. 9.81 x 10^-2 mol
c. 0.0980589 mol
d. 87.5 mol

2. calculate the mass of Chromium (Cr) in magnesium dichromate (MgCr2 O7)
a. 21.6%
b. 23.1%
c. 43.3%

3. A gold wedding band contains 2.3 x 10^22 Au atoms. How many moles of gold are in the wedding band?
a. 3.8 x 10^-2 mol Au
b. 26.2 mol Au
c. 3.8 mol Au
d. 3. 92 mol Au

110mg CaCl2 and 50mg CaSO4 added to 500mL water. solution pH is 8.0 ([H+]=10E-8M ; [OH-]= 10E-6 M). assuming all salts dissociate completely express concentrstion of Ca2+, Cl-, SO42- in mg/L, millimolar, normal (N) units. if total molar concentrations of all speicies in solution is same as in pure water, what are mole fractions of H+, OH-, Ca2+, Cl-, SO42-, H2O

complete and balance the reaction shown assuming 100% neutralization

AL(OH)3 + H2C2O4=? SHOW WORK.

Two 20.0-g ice cubes at –15.0 °C are placed into 255 g of water at 25.0 °C. Assuming no energy is transferred to or from the surroundings, calculate the final temperature of the water after all the ice melts.

I am posting this problem because I've had trouble following the steps listed in similar problems. Please don't answer if you are only going to copy/paste a version of those same steps; It will not be helpful.

When a suspected drunk driver blows 186 mL of his breath through this breathalyzer, the breathalyzer produces an average of 323 mA of current for 10 s. Assuming a pressure of 1.0 atm and a temperature of 24 ∘C, what percent (by volume) of the driver's breath is ethanol?

What is the osmotic pressure, in torr, of a 7.00% solution of NaCl in water when the temperature of the solution is 25 ºC? Enter your answer scientific notation.

To identify a liquid substance, a student determined its density. Using a graduated cylinder, she measured out a 45-mL sample of the substance. She then measured the mass of the sample, finding that it weighed 38.5 g. She knew that the substance had to be either isopropyl alcohol (density 0.785 g/mL ) or toluene (density 0.866 g/mL ).

An experiment requires 53.5 g of ethylene glycol, a liquid whose density is 1.114 g/mL. Rather than weigh the sample on a balance, a chemist chooses to dispense the liquid using a graduated cylinder. What volume of the liquid should he use?

A cubic piece of metal measures 3.50 cm on each edge. If the metal is nickel, whose density is 8.90 g/cm3, what is the mass of the cube?

The specific rate constant for the first-order decomposition of N2O5(g) to NO2(g) and O2(g) is 7.48×10−3s−1 at a given temperature.

1)Find the length of time required for the total pressure in a system containing N2O5 at an initial pressure of 0.110 atm to rise to 0.150 atm .

2)Find the length of time required for the total pressure in a system containing N2O5 at an initial pressure of 0.110 atm to rise to 0.200 atm .

4. Predict in what direction the equilibrium will shift when the volume of the reaction vessel is decreased.

(a) PCl5(g) ⇌ PCl3(g) + Cl2(g)

(b) 2PbS(s) + 3O2(g) ⇌ 2PbO(s) + 2SO2(g)

(c) H2(g) + I2(g) ⇌ 2HI(g)

Determine the pH at the equivalence (stoichiometric) point in the titration of 22 mL of 0.22 M H₃BO₃(aq) with 0.21 M NaOH(aq). The K_a of H₃BO₃ is 5.8 x 10^-10

^{Answer is 11.13}

Ammonia is produced directly from nitrogen and hydrogen by using the Haber process. The chemical reaction is
N2(g)+3H2(g)?2NH3(g) Answer is in kJ / 2moles NH3

Part A.Use bond enthalpies to estimate the enthalpy change for the reaction. Express your answer using two significant figures.

Part C. Calculate the true enthalpy change as obtained using ?H?f values.

Express your answer using two significant figures.

Part D. Compare the enthalpy change you calculate in (a) to the true enthalpy change as obtained using ?H?f values. (essay question)

A 20.0mL sample of a 2.00M potassium sulfate solution is mixed with 14.8mL of a 0.880M barium nitrate solution and this precipitation reaction occurs:

K2SO4(aq)+Ba(NO3)2(aq)?BaSO4(s)+2KNO3(aq)

What is the theoretical yield?

Draw the major alkene product formed from dehydrating the following alcohols?

a) 2-methylcyclohexanol

b) 2,3-dimethylcyclohexanol

c) 1,2,2-trimethylcyclohexanol

d) 2,2-dimethylcyclohexanol (hint: consider carbocation shifts)    

e) 1,2-cyclohexanediol (hint: consider keto-enol tautomerism)

The data set below was collected from a differential, isothermal PFR analyzing the conversion of A +B