perfectly insulated container with no heat capacity is used to mix together the following three samples of water:

I.183.2 grams of water at 23.2 °C

II.32.1 grams of water at 14.2 °C

III.143 grams of water at an unknown temperature.

After the three samples are combined, the final temperature of the combined solutions is 39.0 °C. What is the temperature of sample III before the samples were mixed together?

Select all of the correct statements about reaction rates from the choices below.

A. The lower the rate of a reaction the longer it takes to reach completion.


B. A balanced chemical reaction is necessary to relate the rate of disappearance of a reactant to the rate of appearance of a product.


C. The fastest step in a reaction is called the rate-determining step.


D. The rate of a slow step has more effect on the overall reaction rate than the rate of a fast step.


E. The rate of a reaction is the same as the rate constant of the reaction.


F. Solid catalysts do not affect reaction rates.


G. Reaction rate constants increase with increasing temperature.

The amino acid glutamic acid has the molecular formula C5H9NO4, and the amino acid isoleucine has the molecular formula C6H13NO2. Determine how many moles of isoleucine contain the same number of atoms as 1.96 mol of glutamic acid.

How much ice (in grams) would have to melt to lower the temperature of 354 mL of water from 26 ∘C to 6 ∘C? (Assume the density of water is 1.0 g/mL.)

Piperazine, HN(C4H8)NH, is a diprotic weak base used as a corrosion inhibitor and an insecticide and has the following properties:

pKb1=4.22 pKb2=8.67

For writing the reactions of this base in water, it can be helpful to abbreviate the formula as Pip:

Pip+H2OPipH++H2O??PipH++OH?PipH22++OH?

The piperazine used commercially is a hexahydrate with the formula C4H10N2?6H2O.

a. Calculate the pH after 2.575mL of HCl have been added.

b. Calculate the pH when 12.875mL of HCl has been added.

c. What is the pH at the first midway point?

please don't copy and paste that yahoo answers bs, it doesn't give the right answer.

The corrosion of rebar inside concrete structures is serious issue for the safety and stability of bridges and buildings. The chemistry of corrosion is complex, but a simplified chemical model (iron rusting) is: 4Fe (s) + 3O2 (g) ⟶ 2Fe2O3 (s) ∆H = −1.65 × 103 kJ a) How much heat is released when 1.00 pound of iron rusts? b) If 6.25 × 104 kJ is released, how many kilograms of iron have rusted?

A photometer with a linear response to radiation gave a reading of 690 mV with a blank in the light path and 101 mV when the blank was replaced by an absorbing solution. Calculate

the transmittance and absorbance of the absorbing solution.

Transmittance =

Absorbance =

the expected transmittance if the concentration of absorber is one half that of the original solution.

Transmittance =

the transmittance to be expected if the light path through the original solution is doubled.

Transmittance =

Identify which sets of quantum numbers are valid for an electron. Each set is ordered (n,?,m?,ms).

Check all that apply.

What is the pH of the solution formed when 30.0 g of potassium nitrite (KNO2) is dissolved in 1.00 L of water.

Examples of chemical equilibrium in Nature or in our daily environment (homogeneous and heterogeneous). Can you find examples with small and large extent?

In gluconeogenesis, pyruvate is converted to PEP in two reactions. These reactions include an initial carboxylation followed by a decarboxylation in the second reaction. Based on these two reactions, you would assume that if radio-labeled 14CO2 was present in the reactions, it would not be incorporated into PEP. However, when 14CO2 is present with rat liver cells 14C slowly begins to appear in PEP and eventually on carbons 3 and 4 of glucose. Diagram a series of reactions that would explain this observation. You need to clearly show the location of the radiolabeled 14C in all reactions and indicate any changes in localization with the cells

This is Organic Chemistry Lab, Solvent Extraction.

1. What are the criteria for solubility of organic molecules in water?

2. If methylene chloride was used as the organic solvent in solvent extraction, instead of ether, what would the top layer be in the separation step?

3. What formula was used to calculate interaction of organic compounds with the stationary phase?

4. In the given mixture (liquid-liquid), which compound (be specific) has the weakest interaction with the stationary phase? Why?

What is the pH of a solution containing 0.383
mol L^-1 CH₃COOH and 0.392 CH₃COO^- mol L^-1 ? Round your answer to 2 decimal places.

Calculate the molar solubility of Ag₂CrO₄(s) in (Solubility Product K_sp at 25 °C is 9.0 × 10⁻¹²)

A) pure water

B) in 0.500 L of a solution containing 0.950 g K₂CrO₄