Sunday

February 19, 2017
Total # Posts: 63

**Math**

Another card game. In a new card game, you start with a well-shuffed full deck and draw 3 cards without replacement. If you draw 3 hearts, you win $50. If you draw 3 black cards, you win $25. For any other draws, you win nothing. (a) Create a probability model for the amount ...

*January 29, 2016*

**Math**

Baggage fees. An airline charges the following baggage fees: $25 for the rst bag and $35 for the second. Suppose 54% of passengers have no checked luggage, 34% have one piece of checked luggage and 12% have two pieces. We suppose a negligible portion of people check more than ...

*January 29, 2016*

**Chemistry**

Please check. HCl: dipole-dipole interaction HF: hydrogen bonding TiCl4: ionic bonding? CsCl:ionic bonding

*January 29, 2016*

**Probability #3**

Please check my answers. Thank you! The game of American roulette involves spinning a wheel with 38 slots: 18 red, 18 black, and 2 green. A ball is spun onto the wheel and will eventually land in a slot, where each slot has an equal chance of capturing the ball. Gamblers can ...

*January 28, 2016*

**Probability #2**

Baggage fees. An airline charges the following baggage fees: $25 for the rst bag and $35 for the second. Suppose 54% of passengers have no checked luggage, 34% have one piece of checked luggage and 12% have two pieces. We suppose a negligible portion of people check more than ...

*January 28, 2016*

**Probability #1**

Please check my answers. Thank you! Another card game. In a new card game, you start with a well-shuffed full deck and draw 3 cards without replacement. If you draw 3 hearts, you win $50. If you draw 3 black cards, you win $25. For any other draws, you win nothing. (a) Create...

*January 28, 2016*

**Probabiliy**

Another card game. In a new card game, you start with a well-shuffed full deck and draw 3 cards without replacement. If you draw 3 hearts, you win $50. If you draw 3 black cards, you win $25. For any other draws, you win nothing. (a) Create a probability model for the amount ...

*January 28, 2016*

**Chemistry**

Combusting 44.8L of H2 with 22.4 L O2 (both at STP) results in the formation of 44.8 L of H2O if the reaction is maintained at the same conditions (STP) and goes to completion. Given the heat of formation of water (= -241.8 kK/mol) calculate a) the PV work b) the heat evolved ...

*January 26, 2016*

**Chemistry**

I am stuck on b)... Reacting 1 L of H2(g) with 1 L C2H2(g) (both at STP) results in the formation of 1 L of C2H4(g) if the reaction is maintained at the same conditions (STP) and goes to completion. If this reaction produced 6.3 kJ of heat (absorbed by the surroundings), ...

*January 25, 2016*

**Chemistry -Dr. Bob**

Reacting 1 L of H2(g) with 1 L C2H2(g) (both at STP) results in the formation of 1 L of C2H4(g) if the reaction is maintained at the same conditions (STP) and goes to completion. If this reaction produced 6.3 kJ of heat (absorbed by the surroundings), calculate: a) the PV work...

*January 20, 2016*

**Chemistry-Dr. Bob**

Reacting 1 L of H2(g) with 1 L C2H2(g) (both at STP) results in the formation of 1 L of C2H4(g) if the reaction is maintained at the same conditions (STP) and goes to completion. If this reaction produced 6.3 kJ of heat (absorbed by the surroundings), calculate: a) the PV work...

*January 20, 2016*

**Chemistry- Dr.Bob**

1. Oxygen (O2) is about 20% of our air, with about 80% nitrogen and a bunch of minor components. In Colorado Springs, where I grew up, the elevation is ~ 6500 feet and atmospheric pressure is only around 12 psi (vs. 14.7 psi at sea level). Under those conditions and assuming T...

*January 20, 2016*

**Chemistry- Dr.Bob!**

1. Oxygen (O2) is about 20% of our air, with about 80% nitrogen and a bunch of minor components. In Colorado Springs, where I grew up, the elevation is ~ 6500 feet and atmospheric pressure is only around 12 psi (vs. 14.7 psi at sea level). Under those conditions and assuming T...

*January 20, 2016*

**Chemistry**

Why is the pressure of a gas does not depend on the molar mass of the gas?

*January 18, 2016*

**Chemistry**

Calculate the average kinetic energy of 1 mol of hydrogen molecules and of 1 mol of sulfur hexafluoride molecules at 25 degrees Celsius.

*January 18, 2016*

**Chemistry-Dr.Bob**

You are at your cabin in the woods. Will you be able to take a hot bath tonight if only 0.1 lb of propane remains in the tank? Explain. My answer: No, I will not be able to take a hot bath. By making assumptions and approximations, I got... energy released for combustion is ...

*January 11, 2016*

**Chemistry-Dr.Bob**

Why is gasoline (octane) better than diesal (cetane)?

*January 11, 2016*

**Chemistry-Dr.Bob**

Since most chemical reactions are conducted in containers open to the armisphere, why is the energy transfer associated with a chemical reaction generally expressed as the change in enthalpy? Is it because the enthalpy of reaction measures the change in energy of a chemical ...

*January 10, 2016*

**Chemistry-Dr.Bob**

An unknown piece of metal weighing 100. g is heated to 90.0 degrees Celcius. It is dropped into 250 g of water at 20.0 degrees Celcius. When equilibrium is reached, the temperature of both the water and piece of metal is 29.0 degrees Celcius. Determine the specific heat of the...

*January 9, 2016*

**Chemistry-Dr.Bob, I need you!!!!**

You can mix 100.mL of 1.0 M HCl with 100 mL of 1.0 NaOH, both at 25 degree Celcius. The temperature of your calorimeter rises by 5.98 degree C, and its heat capacity is 100 J/degre C. How much energy is released per mol of H2O formed? My answer: 6x10^6 J per mol H2O I think we...

*January 8, 2016*

**Chemistry-Dr.Bob**

You can mix 100.mL of 1.0 M HCl with 100 mL of 1.0 NaOH, both at 25 degree Celcius. The temperature of your calorimeter rises by 5.98 degree C, and its heat capacity is 100 J/degre C. How much energy is released per mol of H2O formed? My answer: 6x10^6 J per mol H2O

*January 8, 2016*

**Statistics**

Find the interquartile range given these data points: 57,66,69,71,72,73,74,77,78,7879,79,81,81,82,83,83,88,89,94. When I used the TI-84 calculator, I got ... Q1=72.5 Q3=82.5 IQR=Q3-Q1=82.5-72.5=10 But.. When I created a stem and leaf plot I found that Q2= (78+79)/2 =78.5 Q1=72...

*January 7, 2016*

**Statistics**

Find the interquartile range given these data points: 57,66,69,71,72,73,74,77,78,7879,79,81,81,82,83,83,88,89,94. When I used the TI-84 calculator, I got ... Q1=72.5 Q3=82.5 IQR=Q3-Q1=82.5-72.5=10 But.... When I created a stem and leaf plot I found that Q2= (78+79)/2 =78.5 Q1=...

*January 7, 2016*

**Calculus**

Compute the surface area of revolution about the x-axis over the interval. y = x^2, [0, 4] Is it (pi/12)(65^2 - 65)^(3/2)?

*December 7, 2015*

**Chemistry**

Oops.. The subject for this one is calculus, not chemistry

*December 7, 2015*

**Chemistry**

Compute the surface area of revolution about the x-axis over the interval. y = x^2, [0, 4] Is it (pi/12)(65^2 - 65)^(3/2)?

*December 7, 2015*

**Chemistry-Dr.Bob**

What is the increasing dipole moment for CO,CS, and SiS? My answer: SiS<CO<CS Is this correct?

*December 7, 2015*

**Calculus**

How do I integrate sqrt of (1+e^(2x)) if doing u-sub.. u=sqrt of (1+e^(2x)) and ten using partial fraction...?

*December 6, 2015*

**Chemistry**

Can pi bonds be made from d-orbitals?

*December 6, 2015*

**Chemistry**

Name the compound or give molecular formula. 1. Pt(NO2)2 : ? Is it Platinum (II) Nitrite 2. Manganese (II) bromide pentahydrate:? Is it MnBr2 • 5H2O

*December 6, 2015*

**Chemistry**

Calculate the frequency of light associated with the emission from n=5 to n=4 in the hydrogen atom. I got -7.41 x10^13 Hz, but the answer would make sense if it is positive... So does this mean that when the electrons jump from n=5 to n=4, energy is emitted, but the energy has...

*December 6, 2015*

**Chemistry**

Can pi bonds be made from d-orbitals?

*December 6, 2015*

**Grammar**

Is it correct to say.. "This chicken tastes fabulous." Is the word "fabulous" used correctly in this context?

*December 5, 2015*

**Chemistry- Dr.Bob**

Why is cis-PCl3F2 polar and trans-PCl3F2 nonpolar?

*November 28, 2015*

**Calculus**

How do you integrate (x-r)^2 (1/r) (e^(-x/r)) from the interval negative infinity to positive infinity?

*November 27, 2015*

**Calculus**

Integrate e^(-t/r) WITH RESPECT TO dt?

*November 23, 2015*

**Calculus**

How do you integrate e^(-t/r) dt?

*November 22, 2015*

**Calculus**

How do you integrate e^(-t/r)?

*November 22, 2015*

**Calculus**

Integrate x/(6x-5) dx The answer is 1/6 x + 5/36 ln abs (36x-30) + C... But I don't understand why it is 5/36 times ln.. I thought that when you factored out the 5 you would get 5 times ln abs (36x-30)..

*November 21, 2015*

**Calculus**

Calculate integral [0, infinity) xe^(-x) dx

*November 21, 2015*

**Chemistry-Dr.Bob**

A solution is prepared by mixing 50.0mL of 0.001 M HCl and 10.0 mL of 0.200 M NaCl. What is the molarity of chloride ions in this solution? My work: (0.001 mol/L)((0.05 L)= 0.005 mol HCl (0.200 mol/L)(0.01 L)= 0.002 mol NaCl 0.005+0.002=0.007 mol of chloride ions 0.007mol/(0....

*November 20, 2015*

**Calculus**

Integral sign 8x/(x-1) dx Is it 8x+8ln abs (x-1)+C ?

*November 19, 2015*

**Calculus**

Evaluate the integral. Problem#1 Integral sign 4dx/[(x+3)(x^2 +3x) Does it matter where A, B, and C is placed over. Is there a particular order? Is it ..... (A/x)+(B/(x+3))+(c/(x+3)^2=4 Or ... (A/x+3)+(B/x)+(C/(x+3)^2)=4 I am confused because I get different answers each time ...

*November 19, 2015*

**Calculus**

Evaluate using long division. The integral of x/6x-5 dx How do I divide this?

*November 19, 2015*

**math**

Each side of the shaded square is 1 unit. What is the length, width, and area of the figure?

*February 4, 2013*

**math**

The perimeter of a rectangle is 38 centimeters. The length is 7.5 centimeters. What is the width?

*February 4, 2013*

**math**

The area of a rectangle is 45 square inches. One dimension is 5 inches. What is the perimeter?

*February 4, 2013*

**math**

i don't know

*October 20, 2012*

**math**

Jenelle has a blue jug and a red jug, both containing water. The blue jug has 4 gallons and 1 quart of water in it, and the red jug has 2 gallons and 2 quarts of water in it. How much water is in both jugs?

*November 16, 2011*

**math**

The answer is 8 feet remaining. 11-3=8

*November 14, 2011*

**math**

A roll of fabric was 132 inches long. A customer bought 3 feet of the fabric. How many feet of fabric were remaining?

*November 14, 2011*

**math**

6lbs,2oz

*November 14, 2011*

**math**

Holly ordered 2 pounds and 9 ounces of roast beef and 3 pounds and 9 ounces of ham. How much meat did Holly order?

*November 14, 2011*

**math**

add the pounds then add the ounces

*November 10, 2011*

**math**

Holly ordered 3 pounds and 11 ounces of roast beef and 4 pounds and 10 ounces of ham. How much meat did Holly order?

*November 10, 2011*

**math**

Jennie and Millie are sister gorillas. Jennie is 57 kilograms and 663 grams,and Millie is 113 kilograms and 181 grams. How much do the sister gorillas weigh together?

*November 10, 2011*

**math**

60*7=420 420+38=458

*November 10, 2011*

**math**

Levi worked in his neighbor's yard for 7 hours trimming the trees. After trimming, he bagged up the trimmings in 38 minutes. How many minutes did he work in the yard altogether?

*November 10, 2011*

**math**

14, 522

*November 10, 2011*

**math**

A sack of sand measures 21 kilograms and 714 grams,and a sack of yard clippings measures 7 kilograms and 192 grams. How much more does the sack of sand measure than the sack of yard clippings?

*November 10, 2011*

**math**

A roll of fabric was 144 inches long. A customer bought 2 feet of the fabric. How many feet of fabric were remaining?

*November 10, 2011*

**finding area**

Find the area of each square given s = 3.5yd

*March 24, 2011*

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