Homework Help for Chemistry

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

Use the linear 4 carbon alkane and give examples of the different ways in which hydrocarbons can be represented

What is the IUPAC name of this compound

Victoria and Rusty were worried about their infant Bailey since his first trip
to  the  hospital  at  3  weeks  of  age.  At  that  time,  he  had  a  temperature  of
103°F  and  a  runny  nose.  The  emergency  department  physician  examined
the  infant,  but  determined  the  child  was  suffering  from  a  common  cold,
probably  brought  home  by  his  older  siblings,  and  that  all  would  be  fine.
Since  then  Bailey's  health  has  not  improved  and  he  has  experienced  an
unusual  number  of  bacterial  infections.  The  antibiotics  that  Bailey's
pediatrician prescribed have cleared up the bacterial respiratory infections,
but the infection seems to recur.
Bailey is now back at the hospital with pneumonia and his physician
has  ordered  a  number  of  laboratory  tests  as  he  is  now  worried  about
Bailey's immune system. The studies show that Bailey has normal levels of
B cells and T cells, with his immunoglobulin levels and hematology results
listed in Case Study

A chemical engineer must calculate the maximum safe operating temperature of a high-pressure gas reaction vessel. The vessel is a stainless-steel cylinder that measures 40.0cm wide and 48.0cm high. The maximum safe pressure inside the vessel has been measured to be 5.10MPa.

For a certain reaction the vessel may contain up to 2.73kg of dinitrogen difluoride gas. Calculate the maximum safe operating temperature the engineer should recommend for this reaction. Write your answer in degrees Celsius.

Round your answer to 3 significant digits.

A chemistry graduate student is designing a pressure vessel for an experiment. The vessel will contain gases at pressures up to 350.0MPa. The student's design calls for an observation port on the side of the vessel (see diagram below). The bolts that hold the cover of this port onto the vessel can safely withstand a force of 5.00MN.

Calculate the maximum safe diameter w of the port. Round your answer to the nearest 0.1cm.

A 9.00L tank at 13.6°C is filled with 11.8g of dinitrogen monoxide gas and 2.27g of chlorine pentafluoride gas. You can assume both gases behave as ideal gases under these conditions.

Calculate the mole fraction of each gas. Round each of your answers to 3 significant digits.

1) Gas: Dinitrogen monoxide 

Mole Fraction: ?

2) Gas: Chlorine pentafluoride

Mole Fraction: ? 

Sometimes in lab we collect the gas formed by a chemical reaction over water. This makes it easy to isolate and measure the amount of gas produced.

Suppose the CO gas evolved by a certain chemical reaction taking place at 50.0°C is collected over water, using an apparatus something like that in the sketch, and the final volume of gas in the collection tube is measured to be 64.5mL.

Calculate the mass of CO that is in the collection tube. Round your answer to 2 significant digits. You can make any normal and reasonable assumption about the reaction conditions and the nature of the gases.

A gas storage cylinder in an ordinary chemical laboratory measures 3.5cm wide and 14.cm high. This is the label on it.

Contents: N2 gas 

Pressure: 9.92 atm 

If the cylinder is opened and the gas allowed to escape into a large empty plastic bag, what will be the final volume of nitrogen gas, including what's collected in the plastic bag and what's left over in the cylinder? Write your answer in liters.

Round your answer to 2 significant digits.