Sunday

April 20, 2014

April 20, 2014

Total # Posts: 46

**chemistry**

help balance HNO2+HNO3

**math**

jeremy spends 1/4 of his pocket money each week on books.he saves 2/3 of what is left over.if he saves $5 each week,how much weekly pocket money does he receive

**math**

a bottle is 1/4 full of cordial,if 500 ml of cordial is added to it, the bottle is 2/3 full.how many ml does the bottle hold when full

**math **

24874divided by 17 ,which digits should one change in the first number to increase the answer by 100

**math **

24874divided by 17 ,which digits should one change in the first number to increase the answer by 100

**math**

what is the total surface (in square units) of an open-topped box with dimensions L*W*H =9*7*6

**math**

pqrst is a regular hexagon. v is the intersection of pt and su.how big is angle tvs?

**Calculus**

The height (in feet) at time t (in seconds) of a small weight oscillating at the end of a spring is given below. h(t) = 0.2 cos(2t) (a) Calculate the weight's average velocity over the time intervals [1, 2] and [5, 7].

**math**

three sevenths divided by six thirteenths = ?

**math**

sorry,i am still not undrstand

**math**

we decided on a new logo for our brand of shirts.It was to be 3 stripes. How many different logos we make, if we used 3 colors

**math**

sorry, I 'm still not understand

**math**

could u please explain how u work it out,thanks

**math**

how many 2 digit numbers can be written so that the second digit is greater than the digit before it ?

**math**

find the missing number; 8 1 4 5 7 # ;81 4 25 36 ?

**math**

a box contains more than 25 but fewer than 40 balls.When the balls are counted by 3 there is 1 left over.When the balls are counted by 5 there are 2 left over.How many balls are in the box?

**Life orientation**

Describe the life styele cancer and explain factors that contribute to the cancer

**World history**

What was the economy of Syria like before the current revolution? Do you know any good website for it? Please help me!

**Chemistry lab**

I did a copper cycle lab and my final weight of the copper is less than what i started with. Where did the lost copper go?

**Algebra---Variation**

It is a variation problem. I know what the answer is and how to get to the answer I just don't know how I got it. From measurements on many rivers, geographers find that the length of a river that drains a particular "basin" of land is approximately proportional ...

**science**

what quantity of heat must be absorbed to convert 86.1 g of liquid to a vapor at its boiling point, -24.09 c? the heat of vaporization of ch3cl is 21.40

**world history**

sorry it was logged in as my brother's name. Thanks again!

**world history**

Do you know how much it was in France approximately? Do you think there is a source that can help me? :(

**world history**

Can you compare Syria's education level of population with the France's back in the days before the french revolution?

**Chemistry**

In a copper cycle lab, where could have the lost copper might have went? Let's say I did a copper cycle lab and my final weight of the copper is less than what i started with. Where did it go?

**chemistry**

Wait but I tried out the question but I kept getting the wrong answer... So if [mass Hg x specific heat liquid Hg x (Tfinal-Tinitial) ] + (mass Hg x heat fusion) (27.2 * 0.1410 * -61.8) + (27.2 * 11.4) and I got the answer as -598 but the answer is wrong. What am I doing wrong?

**chemistry**

Ahh sorry it was a mistake. Sorry :(

**chemistry**

The freezing point of mercury is -38.8°C, is the only metal that is liquid at room temperature. What quantity of heat energy, in joules, must be released by mercury if 2.00 mL of mercury is cooled from 23.0°C to -38.8°C and then frozen to a solid? (The density of l...

**Chemistry**

My mistake :( Sorry.

**Chemistry**

The freezing point of mercury is -38.8°C, is the only metal that is liquid at room temperature. What quantity of heat energy, in joules, must be released by mercury if 2.00 mL of mercury is cooled from 23.0°C to -38.8°C and then frozen to a solid? (The density of l...

**Chemistry**

Oh never mind I got it. Thank you for your help!

**Chemistry**

But how would you get the mass if the question says 2.00ml and density is 13.6g/cm^3? How do you convert ml to cm^3?

**Chemistry**

The freezing point of mercury is -38.8°C, is the only metal that is liquid at room temperature. What quantity of heat energy, in joules, must be released by mercury if 2.00 mL of mercury is cooled from 23.0°C to -38.8°C and then frozen to a solid? (The density of l...

**Chemistry**

A 237 g piece of molybdenum, initially at 100.0°C, is dropped into 244 g of water at 10.0°C. When the system comes to thermal equilibrium, the temperature is 15.3°C. What is the specific heat capacity of molybdenum?

**chemistry**

calculate the concentration of ions present after the reaction between 13.50mL of 2.00M BaCl2 and 2.50mL of 6.00M H2SO4 i just wanted to check my answers [Ba^2+]=1.69M [SO4^2-]=o.938M [H^+]=0 [Cl^-]=1.50M if they are wrong please explain

**chemistry**

how wold you prepare 2.00L of 1.00M HCl solution using 6.00 M HCl? i already found the volume of 6.00M HCl needed to be .333L. i am confused about how to actually prepare the solution. do i used a volumetric flask or any other glassware?

**chemistry**

the grams of Ba(OH)2 that reacted was 11.99g. but isn't this still of the impure Ba(OH)2 sample? how do i find out the mass of pure Ba(OH)2? thanks for you're help so far

**calculus**

the side of squyare,s, is increasing at a rate of k unites per second. find the rate at which the area of the square is increasing

**Algebra - word problem**

A red ball and a green ball are simultaneously tossed into the air. The red ball is given an initial velocity of 96 feet per second, and its height, t seconds after it is tossed is (-16t^2 + 96t) feet. The green ball is given an initial velocity of 80 feet per second, and its ...

**algebra**

2c-d=-2 d=-4c+20

**statistics**

I meant REASONABLE, sorry. Thanks!

**statistics**

population mean=42.6 standard deviation=12 n=16 M=34.4. Is this mean a reasonable outcome for a sample of n=16, or is this sample mean very different from what would usually be expected? I obtained a z -score of -2.73. Thus, that would make the sample mean a reasonless outcome...

**Statistics**

*librarians intial claim

**Statistics**

Thanks. Would that mean the initial claim was too high?

**Statistics**

The head librarian claims that books have been checked out an average of seven times in the last year. You suspect she has exaggerated the checkout rate and that the mean number of checkouts per book per year is, in fact, less than seven. Using the computerized card catalog, y...

**statistics**

It is known that 60% of people do not respond to mailed questionnaires. In a sample of 20 questionnaires mailed, what is the probability that more than 12 people will respond?

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