Homework Help for Chemistry

4.94 Write the balanced chemical equation for the combustion of ethane, C2H6, and answer these questions. (a) How 
many molecules of oxygen would combine with 14 molecules of ethane in this reaction? (b) If 13.0 mol of oxygen 
is consumed in a reaction, how many moles of water are 
produced? (c) How many grams of ethane are burned if 
4.20 × 1022 molecules of CO2 are produced?

What is a peptide bond

The element silver (Ag) has two naturally occurring isotopes: 109Ag and 107Ag with a mass of 106.905 amu. Silver consists of 51.82 % Ag and has an average atomic mass of 107.868 amu. Calculate the mass of 109Ag

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Chemistry assignment help

Write the Lewis structure for HONO

You prepare serial dilutions by adding 10 grams of meat to the first water blank containing 90ml of sterile water. The sample is shaken to mix the contents and 1ml is then taken and added to the second test tube containing 99ml of sterile water. This process is repeated until you have four samples in total. Samples are then taken as per the diagram and added to TSA plates.

The following colony counts are observed:

Question 1 options:

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What is the dilution of Plate B2?

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How is the count of D1 expressed?

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What is the dilution of Plate C1?

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What is the bacteria count of the Sample of meat (cfu/g)?

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What is the dilution of Blank A?

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Which is the countable plate?

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What is the dilution of the countable plate?

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How many kmol of ethanol are in a 5000kg solution where
𝑤𝑒 = 0.95?
• How many kmol of ethanol are in a 5000kg solution where
𝑥𝑒 = 0.95 (and the rest is water)?

A chemist carefully measures the amount of heat needed to raise the temperature of a 199.0 g sample of a pure substance from 22.3°C to 32.8°C. The experiment shows that 3.87 kJ of heat are needed. What can the chemist report for the specific heat capacity of the substance?

Round your answer to 3 significant digits.

A 37.0g sample of polyisoprene, which has a specific heat capacity of 1.880 J·g−1°C−1, is dropped into an insulated container containing 150.0g of water at 55.0°C and a constant pressure of 1 atm. The initial temperature of the polyisoprene is 5.2°C.

Assuming no heat is absorbed from or by the container, or the surroundings, calculate the equilibrium temperature of the water.

Be sure your answer has 3 significant digits.

The rate of a certain reaction is given by the following rate law:

rate=k[H2][I2]

The rate of the reaction is measured to be 9.0 x 103 M / s when [H2] = 1.7 M and [I2] = 1.9 M. Calculate the value of the rate constant.

Round your answer to 2 significant digits.

A chemist carefully measures the amount of heat needed to raise the temperature of a 1.21 kg sample of a pure substance from 34.3°C to 47.6°C. The experiment shows that 75.6 kJ of heat are needed. What can the chemist report for the specific heat capacity of the substance? Round your answer to 3 significant digits.

A chemist carefully measures the amount of heat needed to raise the temperature of a 409.0g sample of C3H9N from −7.7°C to 12.0°C. The experiment shows that 2.14x10^4 J of heat are needed. What can the chemist report for the molar heat capacity of C3H9N?

Round your answer to 3 significant digits.

Draw the structural formula for the following:

(a) butanoic acid,

(b) 1,3-dibromopentane,

(c) 3-isoprophylhex-1-ene,

(d) cis-pent-2-ene