What is mass (including electrons and without electrons) of one atom of each of these elements (in grams): Chromium, Molybdenum, and Tungsten?

In addition to the molecular orbital treatment of H2, the ground state can be treated by the so-called valence bond (Heitler-London) approach, where individual covalent bonds are combined to form an antisymmetric wave function with spins up and down. Look up this approach and compare the results with the simple MO treatment in terms of bond energy (kJ/mol) and bond distance (pm).

75mL of a 0.111 mol L^-1 solution of butanoic acid(H₃CCH₂CH₂C(=O)OH), and 38 mL of a solution of KOH of molarity 0.101 mol L^-1 are mixed in a 250 mL beaker. What would be the resulting solution's pH?

- Why are electron withdrawing groups (ie nitro group, carbonyl) meta directors?

- Why are electron donating groups o,p-directors? -

Why are halogens deactivators, but o,p-directors

1.) Given the following data:

C2H2(g) + 5/2 O2(g) à2CO2(g) + H2O(l)      ΔH= -1300.kJ

C(s) + O2(g) àCO2(g)                                   ΔH= -394kJ

H2(g) + O2(g) à H2O(l)                                 ΔH= -286kJ

Use Hess’s Law to calculate ΔH for the reaction

2C(s) + H2(g) àC2H2(g)

2.) Calculate ΔH° for each of the following reactions using the data for the enthalpy of

formation in the appendix.

2Na(s) + 2H2O(l)à2NaOH(aq) + H2(g

Explain the relationship between group number and the number of bonds that ions of elements are likely to form.

Please explain in detial!

A solution is 0.017 M in Al3+ and 0.136 M in NaF. If the Kf for AlF63- is 7.0 × 10^19, what is the aluminum ion concentration at equilibrium?

Consider the following system at equilibrium

N2(g)+3H2(g) <------> 2NH3(g)+ heat

Indicatre which way the reaction wil shift when making the following changes

1. Decreasing in the temperture

2. Increasing in the temperture

3. Removing some of NH3

4. Removing some of the H2O

5. Adding some O2

6. Removing some N2

****Pick from these answers ****

A. Forward reaction will increase

B. Reverse reaction will increase

C. There will be no change in either direction

How many grams of dipotassium oxalate (FM 166.22) should be added to 20.0 mL of 0.800 M HClO₄ to give a pH of 4.40 when the solution is diluted to 450. mL? (pK_a1 = 1.27 and pK_a2 = 4.266)
?g

Calculate the freezing point and boiling point of a solution containing 10.6 g of naphthalene (C10H8) in 114.0 mL of benzene. Benzene has a density of 0.877 g/cm3.

Calculate the freezing point of a solution. (Kf(benzene)=5.12∘C/m.)

Calculate the boiling point of a solution. (Kb(benzene)=2.53∘C/m.)

1. A block of an alloy of mass 27.0 g and at a temperature of 277.22 K is placed in a calorimeter containing 41.0 g of water at 357.74 K. If the final temperature of the alloy and water is 303.59 K, calculate the specific heat (in J/g/K) of the metal. The specific heat of water is 4.184 J/g/K. Express your answer to three significant figures in scientific notation.

2.A 0.439 g sample of solid N(CH₃)₄Cl (s) is dissolved in 494 mL of water in a coffee cup calorimeter. Once all of the N(CH₃)₄Cl (s) is dissolved in the water, the final temperature of the solution is found to be 13.59°C. If the initial temperature of the water in the calorimeter was 23.49 °C, calculate the calorimeter constant (in J/K) for the coffee cup calorimeter. Report your answer to three significant figures. The heat of solvation of N(CH₃)₄Cl (s) is 4.08 kJ/mol.

Write the molecular, total and net ionic equations.

Potassium hydroxide +chromium(III) nitrate

Sodium metal + a large excess of water

Potassium perchlorate + sulfuric acid

Barium hydroxide + hydrobromic acid

Phosphoric acid+ magnesium chloride

Hydrocyanic acid+sodium hydroxide

Sulfuric acid+ barium chloride

Silver nitrate+ammonium bromide

Sodium hydroxide+ Aluminum sulfate

Sodium carbonate+ hydroiodic acid

A chemist claims to have discovered a new gaseous element, effuvium (Ef), which reacts with atmospheric nitrogen to form effuvium nitride: 2 Ef(g) + 3 N2(g) 2 EfN3(g) In a container initially containing N2 at 1.00 bar and Ef at 0.75 bar, the total pressure at equilibrium, according to the chemists measurement, is 1.4. Compute Keq for this reaction. Entry field with incorrect answer 0.84 The number of significant digits is set to 2; the tolerance is +/-1 in the 2nd significant digit.