# Posts by andy

Total # Posts: 951

Chemistry
Than from here I need to find: Using the volume of solvent calculated in step 1, calculate how much sulfanilamide will remain dissolved in the mother liquor after the mixture is cooled to 0 degree Celsius? Can you please explain?

Chemistry
thank you!

Chemistry
Please help the question that I got is: Calculate how much 95% ethyl alcohol will be required to dissolve 075g sulfanilamide at 78 degree Celsius. Knowing that solubility of sulfanilamide is 210 mg/ml at 78 degree Celsius, 14mg/ml at 0 Degree Celsius. please explain.

Science
thank you

english/CHECK
1. assail 2. banal 3. mercenary 4. allusion 5. taint 6. appease 7. arbitrary 8. syndrome 9. altruistic 10. euphemism

algebra 8th
ok gat it

algebra 8th
YOU THINK? BUT I HAVE TO DO ALL THE PROBLEM

algebra 8th
ADD OR SUBTRACT> 5.2-2.5 HOW DO I DO THIS?

Wary Inclination Dilemma Sabotage Curt Zeal Demoralised Subsequent Irate Retorted

chem
What is the total pressure in mm Hg of a gas mixture containing argon gas at 0.25 atm helium gas at 350 mm,Hg, and nitrogen gas at 360 torr.

chem
What is the volume in liters of 3.2 moles methane gas, CH4, at 12degrees C and 1.52 atm?

chem
An airplane is pressurized to 650mmHg , which is the atmospheric pressure at a ski resort at 1.30×10^4 altitude.If air is 21 % oxygen, what is the partial pressure of oxygen on the plane?

biochemistry
an intramalecular meds is given at 5.0mg/kg of body weight. if you give 425mg of medicatioon to a pt. what is the ppTIENT weight?

biochemistry
ordered 1.0g of tetracycline to be given every 6 hours. on hand 500mg. how many will we need for 1 days treatment?

Literature
During the Renaissance, people rediscovered the literature of the past. True or False? At that time there was an enormous renewal of interest in and study of classical antiquity. So True, right? Just wanna make sure, Thanks.

personal finance
Sue and Tom Wright are assistant professors at the local university. They each take home about $42,000 per year after taxes. Sue is 37 years of age, and Tom is 35. Their two children, Mike and Karen, are 11 and 9. Were either one to die, they estimate that the remaining family... personal finance Sue and Tom Wright are assistant professors at the local university. They each take home about$42,000 per year after taxes. Sue is 37 years of age, and Tom is 35. Their two children, Mike and Karen, are 11 and 9. Were either one to die, they estimate that the remaining family...

chem
Calculate the specific heat (\rm{J/g \; ^\circ C}) for a 21.5 g sample of a metal that absorbs 685 J when temperature increases from 42.1^\circ C to83.2^\circ C.

chem
Calculate the specific heat (\rm{J/g \; ^\circ C}) for a 18.5-\rm g sample of tin that absorbs 183 {\rm J} when temperature increases from 35.0 ^\circ \rm C to 78.6 ^\circ \rm C.

bio
A typical adult body contains 55 \% water. If a person has a mass of 70.0 kg, how many pounds of water does she have in her body?

Biology

chemistry
Complete and balance the displayed half reaction in neutral aqueous solution taking into account the electrons. Mg(s) → Mg2+(aq)

biology
Does asexual reproduction of sponges depend on time of year, availability of food, or other factors?

Biology

Biology
Under what conditions does asexual reproduction in sponges occur? Does it depend on time of year, availability of food, or other factors?

Science
What is the pH of a 2.62 x 10^-2 M HBr solution? thanks

thanks so much

Which is NOT a chareteristic property of acids? A: react with carbonate to yield CO2 gas B: taste sour C: neutralize bases D; turns litmus red to blue E:reacts with metal to yield H2 gas I reckon its D because isnt it the other way around ? Blue to red ...not...red to blue Any...

what is the hydrogen ion concentration of an aqueous solution with a pOH of 9.262? I got 5.47X 10 ^-10 is this correct? Thanks Andy

the solubility of silver sulfate in water is 0.223%(w/v) at 35 degrees celsius.calculate the solubility product of this salt at this temp. I got 1.46 X 10^-6 M is this right please thanks Andy

Chem/science
what is the ph of 2.62 x 10 ^-2 M HBr solution? I get 5.94 is that right? thanks andy

Chem/science
What is the conjugate acid of HC5H6O4-?? Is it HC5H6O42-?? thanks andy...

Chemistry
Why can't benzene dissolve sodium chloride?

Ineed help with the synonyms and antonyms ex. perfect, frawless is this an antonym or synonym?

SCIENCE?CHEMISTRY***
Dr Bob each time i do a problem on this site I have to print out answer....is there any way you know how to save it to usb stick???? I cant for the life of me find a save feature... also how do YOU when you give us a link to a site ...make it appear in blue and all we have to ...

SCIENCE?CHEMISTRY***
thanks dr bob Andy

SCIENCE?CHEMISTRY***
Am using the inventory method at moment but am stuck on how fill i the inventory for __Agl+__Fe2(CO3)3--> __Fel3+__Ag2CO3 I think the brackets are throwing me Hows this element b4 after ------------------------------------ Ag 1 2 l 1 3 Fe 6 1 CO 3 3 I don't know if this...

SCIENCE?CHEMISTRY***
well done thanks... Andy

SCIENCE?CHEMISTRY***
an 56 Fe 2+ particle has how many protons neutrons amd electrons??? 56 2+ Fe Thanks Andy

SCIENCE?CHEMISTRY***
how many dozens of dust particles are in 2.45 g if each particle has a mass of 2.51 x 10^-4 grams...? I don't have a clue!!!!!! Thanks Andy

SCIENCE?CHEMISTRY***
thanks..... andy

SCIENCE?CHEMISTRY***
DR Bob, can you go through the steps to work this out please.... how many grams of alcohol with a density of 0.900 g/cm ^3 (cm cubed) will have the same volume as 20.0g of mercury,with a density of 13.6 g/cm ^3 Do you have to find the volume of mercury first??? I know the ...

chemistry
thanks..andy

chemistry
The solubility of MnS was found to be 0.000963 g per 700 mL of water. Calculate the solubility product constant (Ksp) for MnS. MnS (s)=Mn2+ (aq) + S2- (aq)

chemistry
The solubility product constant (Ksp) for the dissolution of PbSO4 as represented by the chemical equation is 1.7x10-8. PbSO4 (s)= Pb2+ (aq) + SO42- (aq) Calculate the mass (g) of PbSO4 that dissolves in 1100 mL of water.

SCIENCE/CHEM
thanks so much....andy

SCIENCE/CHEM
Dr Bob Is it true that only TWO molecules of water are required to balance the equation for the reaction of HCL with Calcium Hydroxide.(calcium chloride is the other product....why??? Thanks andy

SCIENCE/CHEM
thanks.... andy

SCIENCE/CHEM
Dr BOB, Can you show me how to do the balanced equation please I am shocking at them Thanks AndyWhats the simple way to explain balancing equations so i get it please....because i am horrible at them... Thanks andy

SCIENCE/CHEM
the purity of zinc is to be determined by measuring the amount of hydrogen formed when a weighed sample of zinc reacts with an excess of HCL acid.the sample weighs 0.198 grams. what amount of hydrogen gas at STP will be obtained if the zinc is 100% pure? need a metric answer ...

SCIENCE/CHEM
thanks..... andy

SCIENCE/CHEM
the volume of a sample of gas is 650.ml at STP. what volumes will the sample occupy at 0.0degrees celsius and 950.torr??? is it 650.ml?

SCIENCE/CHEM
thanks so much ...andy

SCIENCE/CHEM
so 2 X4 ^2 = 32 so 32 is correct ....... thanks andy

SCIENCE/CHEM
thanks...andy

SCIENCE/CHEM
how many electrons can be contained in all orbitals with n=4??????

SCIENCE/CHEM
thanks ...will practice and practice and practice.....andy

SCIENCE/CHEM
I suck at balancing!!!! Sorry Dr BOb you will have to take me on a slow journey on this one....Thanks andy

SCIENCE/CHEM
when the following equation is balanced , what is the sum of the co-efficients? AL2(SO4)^3+Ca(OH)2-->Al(OH)3+CaSO4

science /chem
thanks so much....andy

science /chem
1.250X10^3 ....hows that???

science /chem
thanks I think I acn do that one now...Regards Andy

science /chem
1250.37986 rounded to four significant figures is ??????

SCIENCE/CHEM
thanks...... andy

SCIENCE/CHEM
aha....# of prot and electrons =35 same as atomic number. #of neutons=mass number - atomic number=44 neutrons... so 35 protons,44 neutrons and 35 electrons .....hows that???

SCIENCE/CHEM
does that narrow it down to 35 prot,79 neutrons and 35 electrons? Soory bit lost on electrons... Andy why was there two choices for mass number???

SCIENCE/CHEM
Bromine exists as a mix of bromine 79 and bromine 81 isotopes. an atom of bromine 79 contains: 35 prot.44.neutr.35 electrons 35 prot.and 35 electrons only 44 prot.44 elect and 35 neutr. 35 prot.79 neutr. and 35 electrons 79 protons 79 electrons and 35 neutr. which is correct ...

MATHS !!!
thanks..... andy

MATHS !!!
convert 3.22 mm into cm please

SCIENCE 1
Thanks so much I have always wondered

SCIENCE 1
Does a snails shell grow at the same rate as the snail?? HOW???

chemistry
Thanks Dr bob my brain hurts about this stuff as i try to memorise too much.... thanks for your advice and maybe one day it will all come clear and until then i am still waiting for my AHA...moment sorry till then i need help ....thats why god put brilliant and patient ...

chemistry
Dr bob can you help with my last question for tonights home work please A gas mixture consists of equal parts of methane(molecular weight 16.0) and argon (atomic weight40.0). if the partial pressure of argon is 26.6 kPa what is that of methane in the same units? 10.7 26.7 66.7...

maths
thanks so much

maths
which of the following statements is incorrect? 1 microlitre=10^-6 litres 1 megagram=10^6 grams 1 millimetre=10^3 metres 1 kilogram=10^3 grams 100 centimetres=1 metre thanks andy

CHEMISTRY
so its a trick question as the unwary would say that CH4 and Ar under ideal behavior would be the same and the answer would be 26.7....?? But its obviously worded to catch out the unwary about partial pressure questions? Finally i can rest and the answer is 66.7 NOT 26.7!!!!! ...

CHEMISTRY
ok so P ch4 = 13.67 kPa where do i go from there??

CHEMISTRY
a gas mixtuer consists of equal masses of methane(molecular weight 16.0) and argon (atomic weight 40.0) if the partial pressure of argon is 26.6 kPa, what is that of methane in the same units? 10.7 26.7 66.7 34.1 I am going with 26.7 Do you agree and why please Thanks Andy

CHEMISTRY
I am confused about this statement about water Which of the following is TRUE regarding water only covalent bonds are broken when ice melts (dont think so) all of the staements (A-D) are false energy must be given off in order to break down the crystal lattice of ice to a ...

biology
Non vasculaar plants are those that don't use a vascular system to transport fluids around the plant..such as moss Hope this helps

CHEMISTRY
although helium atoms do not combine to form He2 molecules is it fair to say that London dispersion forces (induced dipole forces)are what attract He atoms weakly to one another? The other choices are dipole-induced dipole forces Hydrogen bonding Ion-dipole forces dipole-...

CHEMISTRY
Wow great!!! thanks very muchyou are right when you look at the shape in the book...it actually becomes obvious Andy

CHEMISTRY
do you agree that HCL is the beast choice for a substance that has both dipersion forces and dipole-dipole forces ? The choices I have are : Br2 HCl H2 CO2 BCl3 HCL is the most sensible answer. Do you reckon so too? thanks andy

Chemistry
thank you so much for that wonderful chart Andy

Chemistry
That would be great if i could see the chart thanks Andy

Chemistry
Dr Bob Can you please confirm for me that only NH3 has a boiling point that does not fit the general trend from these choices NH3 PH3 SbH3 AsH3 many thanks andy I am picking NH3 because of the reason that the larger the compound the greater the boiling point Am I right with my...

science/chemistry
thanks andy

science/chemistry
Dr Bob Although helium atoms do not combine to form He2 molecules. is it true to say that He atoms are weakly attracted to one another from London dispersion forces (induced dipole forces) or is there another force at play? It cant be Hydrogen bonding(there is no hydrogen here...

CHEMISTRY!!/science
A mixture of CO2 and an unknown gas was allowed to effuse from a container. The carbon dioxide took 1.25 times longer than the unknown gas to escape.Which of the following gases could the unknown one be Choices A: Cl2 B: CO C: HCl D: H2 E: SO2 I am going B for this reason: ...

science/chemistry
Oh I see now that you explained it that way!!!! OOPS....sorry yes I took a stab in the dark.....One day I may get this stuff....its going to be a long trip....How do YOU remember all this??? My heads about to explode and I am too young to die!!!!!!!!

science/chemistry
Aha its actually A??? Correct???

CHEMISTRY!!
Which of the following is NOT a postulate of the kinetic molecular theory? A; the average kinetic energy of the particles is directly proportional to the absolute temp. B;the forces of attraction and repulsion between the particles are insignificant C:the moving particles ...

CHEMISTRY!!
Can someone check my answer please: Magnesium metal(0.100 mol)and a volume of aqueous HCL that contains 0.500 mol are combined to react to completion. how many litres of hydrogen gas (measured at STP) are produced choices: 4.42 11.1 22.7 2.27 5.53 I like 2.27... Is this right...

CHEMISTRY!!
I believe that you are right due to the conversion difference and the fact that none of the other answer are even remotly close !!! Thanks DR BOB

CHEMISTRY!!
Calculate the mass in grams of 2.74L of CO gas at 33 degrees celcius and 126.0 kPa I got 3.75 grams Is this right please Thanks

CHEMISTRY
Thanks Dr Bob You rock!!!! Andy

CHEMISTRY
Dr Bob Can you confirm please Given a cylinder of fixed volume filled with one mole of Ar gas,which of the following is CORRECT? (assume that all gases obey the ideal gas laws) A: if the cylinder temp. is changed from 20 to 25 deg.C the pressure will double B:a cylinder of ...

science
For the following reaction if the reaction temperature was increased would the equilibrium shift to the right or the left,not shift at all,or you cant answer the question because Keq is not given? 2SO3(g)<-->2SO2(g)+O2(g)..(deltaH degrees =198kj) Why???

chemistry
Thanks DR BOB, You had me worried for a second there!! Thanks for all your great help on this one Regards Andy

chemistry
Doess this mean I fluked the write answer?? Could you write it out as I have above please with your logical answers so I can go away and study if we are right..I am never comfortable not knowing I have the right workings Thanks andy

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