Posts by TutorCat

Total # Posts: 689

Math
(# of dimes)/(total # of coins)

chemistry-opps again
^I meant molar mass of 4* carbons, because there are actually 4 carbons in Sn(CH3CO2)2 Sorry about that.

chemistry - opps
^I meant molar mass of 3* carbons, because there are actually 3 carbons in Sn(CH3CO2)2

chemistry
First, determine how much of the 325g is carbon. 324g [(molar mass of 2 carbon)/(molar mass of Sn(CH3CO2)2)] Then, convert grams of C to mole by dividing by C's molar mass. Finally, convert the mole to atoms. You know for every one mole there is 6.022 × 10^23 atoms.

algebra
http://www.purplemath.com/modules/systlin4.htm

Math
Standard from should be in this format: Ax +By= C http://www.algebra-class.com/writing-equations-2.html

algebra 2
For the first three, you would have to apply the rational zero theorem ((Broken Link Removed) and then use synthetic division ((Broken Link Removed) to see if the remainder is zero. For the last two, you would group the terms and factor out a common factor method(http://www....

Help Math
incorrect. Law of addition: P(A or B) = P(A)+ P(B)- P(A and B) source: http://www.quickmba.com/stats/probability/

chemistry

Urgent!
how to find mean, median, mode, and range: http://www.purplemath.com/modules/meanmode.htm

science
momentum = (mass)*(velocity)

science
If the amino acid is changed, the tertiary structure (interaction between R groups) will be changed. As a result, the protein's structure(/folding) and therefore function will be different.

Biology
http://utminers.utep.edu/rwebb/html/what_is_a_mutation_.html

Biology
either source: http://en.wikipedia.org/wiki/Mutation

Biology
http://staff.tuhsd.k12.az.us/gfoster/standard/bmut.htm

Chemistry
Every 14 seconds, the isotope's mass is halved.

chemistry
http://scienceworld.wolfram.com/biography/Dalton.html

Chemistry
PV=nRT where P= pressure in atm V= volume in L n =(mass of Ar)/(molar mass of Ar) R=0.082058 L atm mol-1 K-1 T= temperature in Kelvins

Chem
what are the units? http://www.jiskha.com/display.cgi?id=1352484673

Chem
Convert the path length to cm. Plug in Beer's law equation and solve for c. A = ε l c http://www.chm.davidson.edu/vce/spectrophotometry/beerslaw.html

Chemistry
volume = (length)*(width)*(height) density= mass/ volume

chemistry
opps yes your formula is correct!

chemistry
The correct formula: q = mcΔT or c = q/[(m)(ΔT)] http://chemistry.about.com/od/workedchemistryproblems/a/Specific-Heat-Example-Problem.htm

CHEMISTRY
This link is helpful: http://chemistry.csudh.edu/faculty/noel/CHE317L/Extraction%20Experiment.htm read up to X = 8.0 grams of A extracted into the ether. For your question, you would subtract x from 9.81g after you solve for x.

chemistry
volume of sphere = 4/3 π r^3 density = mass/volume

chemistry
1)look at the units. see how this cancels out to give you columb, the SI unit of quantity of electric charge (columb/sec)*(sec) = ? columb 2) divide ? columb by charge on an electron

Chemistry
molality = moles of solute/kilograms of solvent notice how the units cancel out to moles of solute: (moles of solute/kg of solvent)*(kg)= moles of solute

Biology
Molarity (M) = mol / liter = moles/ 1000ml Therefore, 0.8M = 0.8 mol/ 1000 ml Know that the units cancel out to mol: (0.8 mol/1000 ml)*(150ml) = ? mol if you multipy ? mol by the molar mass of NaCl , you would end up with grams of NaCl (? mol)*(__ g/ mol)= ___g NaCl

Chemistry
http://www.jiskha.com/display.cgi?id=1347138502

chemistry
Read Freezing Point Depression Section: http://www.chemistryexplained.com/Ce-Co/Colligative-Properties.html

Geometry
Angle A is 30 more than twice angle B can be written as A = 2B + 30 Because we know that angle A and angle B form a linear pair, we know that A + B = 180 Plug the first equation into the second equation and solve for A. Once you solve for A, plug the know A value into into ...

chemistry

chemistry
1)Convert 25* Celsius to Kelvin. Celsius + 273.15 = Kelvin Plug the given numbers in this formula and solve for final temperature. q = mcΔT where q = heat energy m = mass c = specific heat ΔT = change in temperature = final temperature - initial temperature

MATHS
Hint: Two opposite angles of a parallelogram are congruent, meaning they are equal.

geometry
volume = length x weight x height the ends of the box are square, so height = weight volume = length x height x height plug in the numbers and solve for height

probability
Yes

maths
If 3/5 of the students (you can also think this as 3 out of 5 students) are girls, how many of the 5 students are boys? Present in fraction form. This is the simplified or reduced fraction. fraction = part/whole = number of boys/ number of students Set the reduced fraction = ...

Science
http://www.biologyjunction.com/taxonomy_notes_bi.htm

Science
Here's the chemical equation, but you need to balance it still: CuCl2 + NaNO3 => Cu(NO3)2 + NaCl The reactant that produces the lesser amount of product is the limiting reagent. Here's an example problem: http://www.chem.tamu.edu/class/majors/tutorialnotefiles/...

statistics
https://statistics.laerd.com/statistical-guides/standard-score-3.php

chemistry
Independent variable goes on the x-axis, and the dependent variable goes on the y-axis.

Genral Chemistry

Chemistry
To convert from .95 mol Al to mol H, you would use the coefficients in the balanced equation. Here's an example of a stoichiometry problem: http://www.jiskha.com/science/chemistry/stoichiometry.html

Chemistry
The maximum number of moles of AgCl that could be obtained would be the number of moles of AgCl produced by the limiting reagent.

geometry
ball = sphere Find the surface area of a sphere. A = 4*pi*(radius)^2 source: http://math.about.com/od/formulas/ss/surfaceareavol.htm

Chemistry
1) impure anything should be depressed and/or broad compared to literature melting range 2) pure anything should be at the literature melting range

Chemistry
Here are the rules for counting significant figures: http://academic.umf.maine.edu/magri/PUBLIC.acd/tools/SigFigsAndRounding.html

Chemistry
a)% recovery = [final mass/ initial mass] x 100% b) hint: think about the state of matter of the impurities

physics
See example 2: http://www.cliffsnotes.com/study_guide/Dynamics.topicArticleId-10453,articleId-10417.html

Distance= rate*time Distance upstream = distance downstream Time should be converted to hour b/c the units for rate is in /hour. We know the total time so assign one of the times x (upstream time b/c you would only have to solve for x to get its time) and the other the total ...

science
Density = mass/ volume

math
plug in n for 15 15+(-12) which is the same thing as: 15-12 = ?

chem
Find the molecular weight of AgCl2. That's grams/ 1 mol AgCl2. To convert: (3.6 mol AgCl2)(___g/ 1 mol AgCl2) Notice how the mol unit cancels out and you're only left with the desired grams unit.

chemistry
PV=nRT Solve for V. Here's a sample problem: http://faculty.clintoncc.suny.edu/faculty/Mike.Lawliss/My_webpage/map/pvnrt.htm

statistics
z = (score - mean)/ standard deviation 1)Refer to the z-score chart. Look up the +z-score corresponding to a p-value of ~.8 2)Find score and round up to the nearest 10 interval.

statistics (repeat)
http://www.jiskha.com/display.cgi?id=1323980774

physics
Force = (mass)*(acceleration)

chemistry
Π = iMRT where Π = osmotic pressure in atm i = van 't Hoff factor of the solute. ((Broken Link Removed) M = molar concentration in mol/L R = universal gas constant = 0.08206 L·atm/mol·K T = absolute temperature in K

Chemistry
http://www.jiskha.com/display.cgi?id=1319910648

physics
Force = (mass)*(acceleration)

MATH
x= # kg of cashews 10-x = # kg of pecans (\$8)(x) + (\$9)(10-x) = \$8.40 here's a similar problem: http://www.calculatorsoup.com/calculators/wordproblems/algebrawordproblem1.php

chemistry
2H2+O2->2H2O -convert g of H2 and of O2 each to mol H2O steps 2 & 3: http://www.jiskha.com/science/chemistry/stoichiometry.html -convert the one with lower mol H2O to grams -the reactant that produces the lesser amount of H2O is the limiting reagent and is the mass of water...

statistics
Find the p-value after you find the z-score. z = (x - μ) / σ http://www.ehow.com/how_4555631_calculate-zscore-statistics.html here's an example how to find the p-value: https://controls.engin.umich.edu/wiki/images/3/3e/Screen_shot_z-score.JPG The z-score is 1.13 ...

Physics
due north- aka find y-component due east- aka find x-component http://zonalandeducation.com/mstm/physics/mechanics/vectors/findingComponents/findingComponents.htm

chemistry
rule #2: http://www.seas.upenn.edu/~chem101/oxidationstates.html

chemistry
q = m x Cg x (Tf - Ti) http://www.ausetute.com.au/heatcapa.html

Chemistry
Do the following: 1) Balance the following: H2 + O2 -> H2O 2) Find the limiting reagent. The reactant (H2 or O2?) that produces the lesser amount of the product (H2O). http://www.chem.tamu.edu/class/majors/tutorialnotefiles/limiting.htm

chemistry
manipulate the units so that you end up with meters: (g)*(m/g) then convert to cm by multiply by 100

Chemistry
density = mass/volume mass = (density)*(volume)

Calculating Averages?
http://www.algebralab.org/practice/practice.aspx?file=algebra_averageatomicmass.xml

geometry
solve for x. (2x-3)=0 (x-5)=0 (4x+7)=0

statistics
Use the Empirical Rule. http://www.oswego.edu/~srp/stats/6895997.htm

geometry
http://arnoldkling.com/econ/GMU/growthArith.htm

statistics
http://www.ehow.com/how_4555631_calculate-zscore-statistics.html

Statistics
http://www.jiskha.com/display.cgi?id=1314477006

statistics
http://www.jiskha.com/display.cgi?id=1314477006

statistic
c is correct, but what about a and b? are they possible as well? What is a mode? Here are some examples: http://www.mathsisfun.com/mode.html http://www.purplemath.com/modules/meanmode.htm

physical scince
hint: density=mass/volume

statsitsc
http://stattrek.com/lesson2/normal.aspx

physics
Take the negative reciprocal of the slope. http://www.algebralab.org/lessons/lesson.aspx?file=geometry_coordparallelperpendicular.xml

algebra
Solve for x. This will give you a vertical line at whatever x value you get. Does it intersect the y axis? If not, there's no y-intercept.

statistics
hint: what does small sample size tell you about the standard deviation or variance (is it small or large?)?

Algebra
-10y/13=-4/3 cross multiply and solve for y (-10y)*(3)=(-4)*(13) http://www.mathsisfun.com/algebra/cross-multiply.html

chemistry
Molarity = moles of solute/ liter of solution convert g to mol by dividing molar mass 10g NaOH -> __ mol NaOH

chemistry
http://www.ausetute.com.au/heatcapa.html

math
5cm/20km = 17cm/x km cross multiply: 5x = (20)(17) solve for x.

chemistry
http://chemistry.bd.psu.edu/jircitano/soluble.html

math
http://www.mathsisfun.com/greatest-common-factor.html

Science
http://www.jiskha.com/science/chemistry/stoichiometry.html

Algebra 1
combine like terms: http://www.purplemath.com/modules/polydefs2.htm

algebra/trignometry
Draw a triangle. Label the angles x, y, and z. Label what are given. Determine whether what you have is SOH, CAH, or TOA. http://www.mathsisfun.com/algebra/sohcahtoa.html

multiplying decimals
http://www.mathsisfun.com/multiplying-decimals.html

arithmetic
http://www.mathwarehouse.com/algebra/averages/

chemistry
molality = moles of solute/ kg of solvent

statistics
sigma = sqrt [np(1-p)] http://stattrek.com/Lesson2/Binomial.aspx

calculus
Look at example 2: http://tutorial.math.lamar.edu/Classes/CalcI/DefnOfDerivative.aspx

chemistry

Chemistry
Calculate the Empirical Formula given 16.37% H and (100-16.37)% C. Refer to Example #2. http://www.chem.tamu.edu/class/majors/tutorialnotefiles/empirical.htm Use PV=nRT. n=mass/molar mass units: P=atm, V=L, T=K R=0.08206 atm*L/mol*k Solve for molar mass and calculate the ...

MATH
(1/6)^(3x) = 36 ^(2-x) hint: 1/6 = 6^(-1) & 36 = 6^2

MATH
(-1/18)*(r)=(1/6) find r. geometric progression: ar^(n-1) a=1st term r=ratio n=nth term http://www.mathsrevision.net/alevel/pages.php?page=33

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