Homework Help for Chemistry

A sample of gas occupies 54.0 mL at 24.0C. What is the volume of the gas at 80.0C?

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2. Which of the following is not a redox reaction? 

A    

B   

C   

D   

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4. Lewis Acid/Base Interactions. All coordination complexes consist of Lewis acid/Lewis base interactions. Draw the Lewis structures of the reactants and products listed below and provide an arrow-pushing mechanism for their interactions. Your assigned reading will help you here!

a)   

b)   

c)    

Matter, Trends, and Chemical Bonding
1) Analyze the properties of commonly used chemical substances and their effects on human health and the environment, and propose ways to lessen their impact.

2) Investigate physical and chemical properties of elements and compounds, and use various methods to visually represent them

3) Demonstrate an understanding of periodic trends in the periodic table and how elements combine to form chemical bonds.

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4. Consider the following reactions of four metals - D, Z, Q and X.

From these data it can be deduced that:

A  X is more reactive than Q

B  Q is the most reactive metal

C  Z is a stronger reducing agent than X

D D is a stronger reducing agent than Q

Can someone please help me with this question? Thanks in advance :)

5  The heat of combustion of methane is -890 kJ .

b  Determine the mass of methane, in g, which has to be burnt in order to heat 500 mL of water from 20.0C to boiling. Assume all the heat released was used to heat the water.

Calculate the formula of the hydrate CuSO4 • X H2O. Use this data from the trial and make sure to show with correct significant figures. Use unit factor to calculate moles.

  1.) a. determine the mass of the original hydrate sample AND after heating.   b. determine the number of moles of the hydrate after heating.   c. determine the mass of the water that was released.   d. determine the number of moles of water.   e. write the correct formula for the hydrate and the correct name of the hydrate.   Please help and thank you!

The values for cysteine are shown below. 

At what pH will a solution of 2.2 M cysteine be isoelectric? 

Also, how do you determine if n-terminus or c-terminus gets deprotonated or protonated?

What is the relationship between the absorbance versus % transmission for a xylene cyanol sample? Indicate what wavelengths of light associated with each of these two measurements.

Do you think a standard curve based on % Transmission would look the same as the Absorbance curve above? Explain your answer.

At 363 K, this reaction has a 𝐾c value of 0.0207.
              2X(g)+3Y(g)↽−−⇀Z(g)

Calculate 𝐾p at 363 K. Note that the pressure is in units of atmosphere (atm).

𝐾p=

If 15.0 g of NaOH reacts with excess sulfuric acid, how many grams of sodium sulfate would result?

Could you please explain how you arrived at the answer please, and how to determine the charge of each group. Thanks

Recrystallization

1/

The liquid used to wet the filter paper and wash the crystals was:

Cold recrystallization solvent

The mother liquor from the same solution

Hot recrystallization solvent

Tap water

Solutions, suspensions, colloids and emulsions.

Watch the Echo demonstration of the different mixtures, record the results and answer the questions.

1. Add 0.5 gm of salt (NaCl) to a 50 ml beaker containing about 25 ml of water.

Swirl gently.

What happens to the salt crystals?

Is this a solution, suspension or colloid? Why?

2. Discard the salt water and this time add 0.5 gm of sand to 25 ml of water.

Swirl gently.

What happens to the sand particles?

Is this a solution, suspension or colloid? Why?

3. Discard the sand solution and place 25 ml of water in the beaker. Sprinkle 0.5 gm of gelatin on the surface. Swirl gently and then allow to stand for 10 minutes. Clean all glassware.

What happens to the gelatin?

Is this a solution, suspension or colloid? Why?

4. Mark a test tube at 2 cm and at 4 cm from the bottom. Fill to the 2 cm mark with vegetable oil and to the 4 cm mark with water. Use parafilm to cover tube and mix vigorously. Let the tube stand for 10 minutes Explain what happens.

5. Now add 2 drops of dishwashing soap to the test tube of water and oil and again mix vigorously. Let stand for 10 minutes.

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1. What is the IUPAC name for the following compound?