archy

I ask one girl out and she said not now. Is she mean no or she still have feeling for me but just want more time?

Why do chemists who do quantitative work with liquids prefer to use molality over molarity as a measure of concentration?

1.

The volume of a mixture may not be just additive of the volumes of its components.

2.

The volume is affected by changes in temperature and pressure.

3.

Thermodynamically, mass is a conserved quantity.

4.

The number of moles of solute is a conserved quantity.

The equilibrium constant for a reaction

text A  +  B ⇔ Y +  Z end text

is Kc = 0.1.

What amount of A (in mol) must be mixed with 4 mol of B to yield, at equilibrium, 1.1 mol of Y in a volume of 1L? - At the beginning there is no amount of Y or Z present. Give your answer to 2 sig. fig. including trailing zeros.

When you dissolve 2.5 mol of Ethanol in 1 kg of water, there is 1 ethanol molecule for how many water molecules? - Give your answer to 3s.f.

Considering the SN1 and SN2 mechanisms of nucleophilic substitution, it would be expected that the entropy of activation for the rate-determining step would be

positive for SN1 and for SN2.

about the same for SN1 and SN2.

negative for SN1 and for SN2.

positive for SN1 and negative for SN2.

negative for SN1 and positive for SN2.

For a biochemical reaction involving the binding of a sugar to a particular site in a protein, would you expect

the entropy of activation to be positive and the Arrehnius A factor to be relatively small?

the entropy of activation to be zero and the Arrhenius A factor to be 1?

the entropy of activation to be positive and the Arrehnius A factor to be relatively large?

the entropy of activation to be negative and the Arrehnius A factor to be relatively large?

the entropy of activation to be negative and the Arrehnius A factor to be relatively small?

which one is it

2-chloropropane decomposes to propene and HCl with first-order kinetics in the temperature range 360 - 450°C. The half-life at 375 °C is 44.5 minutes. The activation energy is known to be 211 kJ mol-1.

What is the rate constant at 445°C(expressed in s-1)?

The presence of a catalyst reduces the activation energy of a certain reaction by 12 kJ mol-1.

By what factor does the rate increase in the presence of the catalyst at 370 K, assuming all other factors remain equal?

The initial stages of the high-temperature reaction between NH3(g) and NO2(g) follow second order kinetics.

Given that the rate constant is 0.385 mol-1 L s-1 at 600 K and 16.0 mol-1 L s-1 at 716 K, deduce the value of the activation energy. Express your answer in kJ mol-1.

The rate law for the overall reaction

H2(g) + Br2(g) → 2 HBr(g)

has the form

v = k [H2] [Br2]3/2 / ([Br2] + k′ [HBr])

to find partial pressure do you use gage or absolute pressure

A reaction exhibits the stochiometry:

2 text A end text space left right double arrow text Y end text space plus thin space 2 text Z end text

In a volume of 16.4 L we start with 8.3 mol of A and none of substances Y and Z. At equilibrium there are 1.5 mol of A left.

Calculate the equilibirium constant Kc.

The equilibrium constant for a reaction

text A  +  B ⇔ Y +  Z end text

is Kc = 0.2.

What amount of A (in mol) must be mixed with 4.8 mol of B to yield, at equilibrium, 1.8 mol of Y in a volume of 1L? - At the beginning there is no amount of Y or Z present.

A chemical equilibrium is:

text A end text space left right double arrow 2 text B end text

A volume of 9 L is filled with 6 mol of A with none of B present. At equilibrium 1 mol of A remain.

Calculate the equilibrium constant, Kc.

Sodium Chlorite (NaClO2) bleaching agent. Sodium Chlorite can be made by reacting ClO2 (gas) with hydrogen peroxide and sodium hydroxide to give sodium chlorite, water and oxygen:

2𝐶𝑙𝑂2 +𝐻2𝑂2 +2𝑁𝑎𝑂𝐻 → 2𝑁𝑎𝐶𝑙𝑂2 + 2𝐻2𝑂 + 𝑂2

Any unused ClO2 would break down into chlorine gas and oxygen, and the peroxide would break down into water and oxygen. The chlorine and.oxygen would leave the mixture giving a chlorite solution,

2𝐶𝑙𝑂2 → 𝐶𝑙2 + 2𝑂2

2𝐻2𝑂2 → 2𝐻2𝑂 + 𝑂2

A horizontal cylindrical steel (density 0.284 lbm/in3) storage drum with

hemispherical ends is partially filled with oil (density 900 kg/m3).

Assuming that the space above the oil can be ignored, develop a calculates (in kg) the dry mass of the drum, the wet

mass (drum + contents) of the drum, Dimensions of the drum are given in

imperial units (outside diameter inches, length of cylindrical shell ft,thickness of metal wall in). Express the filling level asa percentage of the

total volume available.

HTT – The drum material here is steel, but some containers will be made

of other types of materials (PVC, cast iron). For the next Tier, why not

modify your sheet to allow the user to select other materials from a built

in list.

Sodium Chlorite (NaClO2) is a white solid that is used in water

disinfection and purification, and as a bleaching agent. Sodium Chlorite

can be made by reacting ClO2 (gas) with hydrogen peroxide and sodium

hydroxide to give sodium chlorite, water and oxygen:

2𝐶𝑙𝑂2 +𝐻2𝑂2 +2𝑁𝑎𝑂𝐻 → 2𝑁𝑎𝐶𝑙𝑂2 + 2𝐻2𝑂 + 𝑂2

Any unused ClO2 would break down into chlorine gas and oxygen, and

continue in answer thing

Sodium Chlorite (NaClO2) is a white solid that is used in water

disinfection and purification, and as a bleaching agent. Sodium Chlorite

can be made by reacting ClO2 (gas) with hydrogen peroxide and sodium

hydroxide to give sodium chlorite, water and oxygen:

2𝐶𝑙𝑂2 +𝐻2𝑂2 +2𝑁𝑎𝑂𝐻 → 2𝑁𝑎𝐶𝑙𝑂2 + 2𝐻2𝑂 + 𝑂2

Any unused ClO2 would break down into chlorine gas and oxygen, and

A horizontal cylindrical steel (density 0.284 lbm/in3

) storage drum with

hemispherical ends is partially filled with oil (density 900 kg/m3

).

Assuming that the space above the oil can be ignored, develop a

spreadsheet that calculates (in kg) the dry mass of the drum, the wet

mass (drum + contents) of the drum, Dimensions of the drum are given in

imperial units (outside diameter inches, length of cylindrical shell ft,

thickness of metal wall in). Express the filling level as a percentage of the

total volume available.

HTT – The drum material here is steel, but some containers will be made

of other types of materials (PVC, cast iron). For the next Tier, why not

modify your sheet to allow the user to select other materials from a built

in list.

Borazine, with formula B3H6N3 has been described as inorganic benzene, due

to the similar structure it has to C6H6.

(i) Draw a structure for borazine, making use of this analogy.

(ii) The bond length expected for a B-N single bond is ca. 151pm and for a

B=N double bond 131pm. In borazine the boron-nitrogen bond lengths

are found to be all the same length (144pm). Account for this result.

(iii) Would you expect an analogous compound of formula B3H6P3 to exist?

Explain your answer.