Friday
April 29, 2016

# Posts by Saira

Total # Posts: 194

chemistry
what is the molarity of the solution comtaining 2.5g of acetic acid in 75g of benzene
April 7, 2016

Math
November 17, 2015

Math
November 17, 2015

Math
Tony is 2/3 as old as Pete; the difference in their age is 4 years. How old is Pete?
November 17, 2015

Math
If Rita can type 55 words a minute, how many minutes to the nearest minute will it take her to type a 1695-word article?
July 5, 2015

physics
A person of mass 60 kg is standing on a raft of mass 40kg in a lake. The distance of a person from bank is 30m. If a person starts running towards bank with velocity 10m/s then his distance from bank after 1s will be ?? And explain with diagram and proper steps
September 16, 2014

science
when people remember memories after a memory loss, would you call those memories flashbacks or is there a different term? and is it possible for someone to lose memory for a specific event but remember everything after that? what is the term and are there any websites which ...
January 1, 2014

Health
how can a disabled wheelchair person lead a normal life? how do they cook? etc
April 10, 2013

Math!!!! *plz help*
Use Brackets. Write Each Expression so that it equals the number in blue. a) 8+2x5 50 b) 6x3+1 24 c) 1+6x3+1 25 d) 2+8x5-1 49 e)7+14\7-5 14 f)12\2x5-4 2 Help Me Please i dont get what to do and how to.... ( \ stands for division)
September 10, 2012

Math
50 24 25 49 14 2 = numbers in blue in my textbook
September 10, 2012

Math
Use Brackets. Write Each Expression so that it equals the number in blue. a) 8+2x5 50 b) 6x3+1 24 c) 1+6x3+1 25 d) 2+8x5-1 49 e)7+14\7-5 14 f)12\2x5-4 2 Help Me Please i dont get what to do and how to.... ( \ stands for division)
September 10, 2012

English
What does fantastical mean? My essay topic is compare the fantastical in Poe and lawrence's "the rocking horse"
June 7, 2012

chemistry
What is the approximate energy required to raise the temperature of 5 L of air by 230 °C? The volume is held constant. (Assume air almost entirely consists of nitrogen, oxygen, and argon, and that it is initially at 273 K. Cv(specific heat) for nitrogen=20.7,oxygen=21 and ...
April 17, 2012

chemistry
What is the approximate energy required to raise the temperature of 5 L of air by 230 Â°C? The volume is held constant. (Assume air almost entirely consists of nitrogen, oxygen, and argon, and that it is initially at 273 K. Cv for nitrogen=20.7,oxygen=21 and argon=12...
April 17, 2012

languagge
whats the natural resources of Japan ?
November 14, 2011

4> OOps you have to spin it 3 times not 2 times
June 6, 2011

My sister in grade 5 needs help but i dunt exactly know how to do the answers myself, so if someone can help me out i can explain to her better. Thanks 3. You are using a tree diagram with 12 branches to show the possible outcome of a probability experiment What might the ...
June 6, 2011

science
a ball is thrown from a point 100m above the ground with speed 20m/s.find the velocity,direction and magnitude with which it strikes the ground?
June 1, 2011

sciene
thanks alot ms.sue
April 23, 2011

sciene
how can solar power work at night
April 23, 2011

health
thank you Ms.sue and bobpursley.
March 7, 2011

health
1. Carbohydrates 2. Protein 3. Fat 4. Minerals 5. Vitamins 6. Water
March 7, 2011

health
March 7, 2011

science 5
im not sure
February 24, 2011

science 5
ts the est source of power in toronto please tell me i need help
February 24, 2011

health
i also need the names of the different fast food so i can research there ingrdients. thank you
February 1, 2011

health
thanks
February 1, 2011

health
need help
February 1, 2011

health
unhealthy fast food you can find list ingredents
February 1, 2011

ancient civillation
we stared this unit 2 days ago and we have a project on them they are china egypt and greaPr
January 15, 2011

ancient civillation
which lasted the longest. which lasted shortest. which began earliest. which began latest. Also what were the civillations that lasted 3000 years or more. please help i`m confused.
January 15, 2011

social studies
thank you writeacher
January 14, 2011

social studies
January 14, 2011

social studies
January 14, 2011

math
A spool has a radius of 5cm . A string is 8.8 m long. How many times can the string be wound around the spool?
December 3, 2010

math
what is 20 Jamaican dollars equal in Canada.
July 12, 2010

Chemistry
nvm i got it had to conver delta S J/k to kj/k
April 22, 2010

Chemistry
How do i calculate: What is is ΔG° at 25 °C? 2O3(g) → 3 O2(g) ΔH° = -284 kJ ΔS° = 139 J/K i know the equation is: ΔG°= ΔH°- t (ΔS) im not getting right answer
April 22, 2010

spelling
April 21, 2010

spelling
i also cant figure words for decades
April 21, 2010

spelling
perimeter: meter ,merit litre:let
April 21, 2010

spelling
can you list some smaller words that are in perimeter and litre. thank you
April 21, 2010

writting
Thank you . You helped me alot.
April 7, 2010

writting
Instead of these words i want more powerful words that mean the same but is more powerful.
April 7, 2010

writting
what does hewn mean? Also can i get a list of synonyms for objects , cutting , impact and act. please help!
April 7, 2010

maybe there is 6 pennies and 30 dimes.
April 7, 2010

heres more rhyming worlds: flick , Kick.
April 5, 2010

I came up with the same number as chelsea.
April 5, 2010

Chemistry
IN the polystyrene beaker, mix 20mL of 0.1 M Acetic acid and 25mL of 0.1M Sodium Acetate and immediately measure the pH. Remove the electrode and add 5ml of 0.1 M HCl to this buffer. Stir the solution and measure the pH. _______________ INFO: concentration of acetic acid= 0.1M...
March 28, 2010

Chemistry
Yes they go together
March 24, 2010

Chemistry
Part A: Unknown Acid use 1gram and mix with 120 mL of distilled water Determine the concentration of the acid by titrating with 0.0998 M of NaOH Concentration of NaOH= 0.0998M Volume of NaOH= 3.5 mL # moles of NaOH= Initial Concentration of Weak Acid- Show Calculation of Ka ...
March 24, 2010

Chemistry
Hydrolysis of Salt: Using the universal indicator we had to determine the pH of sodium acetate, and the results i got was pH- 8.5 . Now i have to explain this with a equation to show hydrolysis. I don't know how to write it out but, Sodium is not hydrolyzed and acetate is ...
March 24, 2010

Chemistry
Calculate the pH of a 0.10 M solution of barium hydroxide, Ba(OH)2.
March 2, 2010

duratioon
how to calculate duration of a balance sheet
February 28, 2010

February 15, 2010

Before farms before did not have electronics so it was hard to to work.Also Farmers did not use fertilizers so it also was hard to grow crops.And there is more about the lord and peasants.
February 15, 2010

explain how farms today are different than medieval farms . Compare the farms. list a lot of differences and same things . please help!
February 15, 2010

what type of games do village people now play.
February 15, 2010

Thanks Ms.sue!!!
February 14, 2010

February 14, 2010

You have GREATER chance with box b because there is only 1 yellow marble and there is 2 red marbles so most of the marbles are red,but box a has almost the same amount of red and yellow marbles.
February 14, 2010

Chemistry
So its deltaTf = Kf * m m= 9.70°C/-1.86°C kg/mole = 5.2515 m (molality) What i'm not sure about is, if Delta Tf= in this equain is tfinal-t initial or its the freezing point as ypu mentioned .5C
February 3, 2010

Chemistry
Hey guys I did a lab and I have to answer the questions relating to the lab. I did question can someone please check if these are accurate 1. Calculation to Determine the molecular weight of unknown substance Mass of unknown used: 2.0232 g Mass of water used: 50.0 g (0.05kg) ...
February 3, 2010

Chemistry
Raoult's Law and Ionic or Organic Solutions At 55.0 C, what is the vapor pressure of a solution prepared by dissolving 62.8 g of LiF in 247 g of water? The vapor pressure of water at 55.0 C is 118 mmHg. Assume complete dissociation of the solute.
January 25, 2010

If 4.55 g of sodium sulphide and 15.0 g of bismuth nitrate are dissolved in separate beakers of water which are then poured together, what is the maximum mass of bismuth sulphide, an insoluble compound, that could precipitate? What reactant was the limiting reactant? Na2S + Bi...
January 15, 2010

Chemistry
Rank the following ionic compounds by lattice energy. Highest to Lowest LiCl MgO Na2O Beo Na2S
January 15, 2010

Is this Correct? 3Na2S + 2Bi(NO3)3 -->Bi2S3 + 6Na^+(aq)+ 6NO3-(aq) A.) 4.55g/ 78.05= 0.059 moles Na2S 15.0g/ 394.99= 0.038 moles Bi(NO3)3 B.) Na2S= 0.059/ 3= 0.019 Bi(NO3)3= 0.038/ 2= 0.019 (Just for general knowledge if this was a different question, and after dividing by ...
January 14, 2010

If 4.55 g of sodium sulphide and 15.0 g of bismuth nitrate are dissolved in separate beakers of water which are then poured together, what is the maximum mass of bismuth sulphide, an insoluble compound, that could precipitate? What reactant was the limiting reactant? Na2S + Bi...
January 14, 2010

Art
I need help understanding the Principles and Elements of Visual Arts with the help of images which examplify them...
November 4, 2009

psychology
Well elemenatry my dear isn't it obvious that the correct choice is B.
October 20, 2009

gr.10 mathh!
factor the equation: -6x^2+15x+36 please show me the steps in answering this problem. thanksss..)
September 19, 2009

Chemistry
Which of the following mixtures would result in buffered solutions when 1.0 L of each of the two solutions are mixed? a) 0.10 M NaCl and 0.10 M NaNO2 b) 0.10 M NaCl and 0.10 M NH4Cl c) 0.10 M CH3NH2 and 0.15 M CH3NH3Cl d) 0.10 M HCl and 0.05 M NaNO2 e) 0.10 M HCL and 0.20 M ...
August 11, 2009

Chemistry
I am not really sure how to do this: Calculate the pH when 1.0*10^-3 moles of solid NaOH is added to a) One liter of 9.1*10^ -6 M HCL b) One liter of a solution containig 0.05 M CH3COOH and 0.1 M CH3CooNa
August 11, 2009

Chemistry
Buffers- Common Ion effect IS this Correct Calculate the pH of a aqueous solution containing 0.15 M HNO2 and 0.20 M NaNO2 (aq). The Ka of nitrous acid is 4.0*10^-4. HNO2 + H20 <--> NaNO2- + H30^+ Inital 0.15 0.20 X Final 0.15 0.20 Ka= [H30+][NaNO2]/ [HNO2] 4.0*10^-4 = [...
August 11, 2009

Chemistry
Hydrolysis of Salt: Using the universal indicator we had to determine the pH of potassium chloride, and the results i got was pH- 7.5 . Now i have to explain this with a equation to show hydrolysis. I dunno how to write it out, but i think KCL should be neutral.
July 19, 2009

Chemistry
This is whta i have so far...The Ka is 1.8*10^-5 so pKa is= -log(1.8*10^-5) = 4.74 pH= pKa+log ([C2H3O2^-]/[HC2H3O2]) = 4.47+ log ([C2H3O2^-]/[HC2H3O2])
July 19, 2009

Chemistry
I actually posted this up before and Gk helped out but i don't understand the steps what do i enter for the pka for the first one? __________________________________________ I did an experiment on Buffers: In a polystyrene beaker, mix 20 ml of 0.1M Acetic acid ad 25 ml of ...
July 19, 2009

Chemistry
OMg iforgot i posted it up befoe sorry
July 16, 2009

Chemistry
A 80.0 mL volume of 0.25 M HBr is titrated with 0.50M KOH. Calculate the pH after addition of 40.0 mL of KOH.
July 16, 2009

Chemistry
A 80.0 mL volume of 0.25 M HBr is titrated with 0.50M KOH. Calculate the pH after addition of 40.0 mL of KOH.
July 16, 2009

Chemistry
I did an experiment on Buffers: In a polystyrene beaker, mix 20 ml of 0.1M Acetic acid ad 25 ml of 0.1 M sodium acetate and immediately measure the pH. Remove the electrode and add 5 ml of 0.1 M HCL to this buffer. Stir the solution and measure the pH. This is my data: Conc.of...
July 16, 2009

Chemistry
A 0.040M solution of a monoprotic acid is 14% ionized. Calculate the Ka for the weak acid. ---------------- so: HX <---> H+ + X- Ka= [H+][X-]/ [HX] Since its a monoprotic acis i know the concentration of H and X will be equal And the HX will be 86% (100%-14%) BUt i m not...
July 15, 2009

Chemistry
Imagine that you are in chemistry lab and need to make 1.00 L of a solution with a pH of 2.70. You have in front of you * 100 mL of 6.00×10−2 M HCl, * 100 mL of 5.00×10−2 M NaOH, and plenty of distilled water. You start to add HCl to a beaker of water ...
July 9, 2009

Chemistry
[CH3COOH] + [CH3COO-]= 0.100 M pH = pKa + log [CH3COO-] / [CH3COOH] 5.00 = 4.760 + log [CH3COO-] / [CH3COOH] 10^0.24 =1.74 = [CH3COO-]/ [CH3COOH] I have an idea how to solve it but i dunt know how to get the M of CH3COO AND CH3COOH
July 9, 2009

Chemistry
A beaker with 150 mL of an acetic acid buffer with a pH of 5.00 is sitting on a benchtop. The total molarity of acid and conjugate base in this buffer is 0.100 M. A student adds 5.60 mL of a 0.280 M HCl solution to the beaker. How much will the pH change? The pKa of acetic ...
July 9, 2009

Chemistry
A new potential heart medicine, code-named X-281, is being tested by a pharmaceutical company, Pharma-pill. As a research technician at Pharma-pill, you are told that X-281 is a monoprotic weak acid, but because of security concerns, the actual chemical formula must remain top...
July 7, 2009

June 16, 2009

A polygon can be any shape not just shapes with 4 angles. anonymous is right.
June 10, 2009

Chemistry
WHen i did it the answers i got was order of reaction m= 2 and k = 4.6 Can someone please double check
June 2, 2009

Chemistry
i need help with a rate law question: The reaction is 2ClO2(aq) + 2OH -(aq)---> ClO3-(aq)+ ClO2-(aq) + H2O(l) Experiment 1: [ClO2]0= 0.0500 [OH-]0= 0.100 INITIAL RATE= 5.75*10^-2 Experiment 2: [ClO2]0= 0.100 [OH-]0= 0.100 INITIAL RATE= 2.30*10^-1 Experiment 3: [ClO2]0= 0....
June 2, 2009

thank you i got the answers
May 29, 2009

HENRY'S LAW I did the first one im not sure how to do the 2 and the 3rd question. 1. What is the Henry's law constant for CO2 at 20{C}? C=kP K=c/p = 3.70*10^-2/1.00atm= 0.037 2. What pressure is required to achieve a CO2 concentration of 6.00×10−2 at 20{C...
May 29, 2009

Chemistry..
oops sorry when i multiply (0.002 Litres)(0.138) the answer i get is 0.000276 and kg was an accident
May 29, 2009

Chemistry..
A protein subunit from an enzyme is part of a research study and needs to be characterized. A total of 0.180 g of this subunit was dissolved in enough water to produce 2.00 mL of solution. At 28C the osmotic pressure produced by the solution was 0.138 atm. What is the molar ...
May 29, 2009

thank you
May 27, 2009

Hey guys I did a lab and I have to answer the questions relating to the lab. I did question can someone please check if these are accurate 1. Calculation to Determine the molecular weight of unknown substance Mass of unknown used: 2.0 g Mass of water used: 50.0 g (0.05kg) Kf...
May 27, 2009

Chemistry
A mass of 0.630 g of NaCl is dissolved in 525 g of water. CAlculate the molality. mass of NaCl= 0.630g mass of H20= 525g molar mass of NaCl= 58.44 This is what i did it keeps telling me the answer is wrong. Convert grams to moles of NaCl 0.630 * 1 mol NaCl/58.44= 0.01078 ...
May 21, 2009