Wednesday
June 19, 2013

Posts by Elle


Total # Posts: 86

Chemistry
A coffee-cup calorimeter initially contains 125 g water at 24.2 degrees celsius. Potassium bromide (10.5 g), also at 24.2 degree celsius, is added to the water, and after the KBr dissolves, the final temperature is 21.1 degrees celsius. Calculate the enthalpy change for diesel...

Biology
In ion exchange chromatography, why do you have to be careful not to disturb the resin bed or let air enter the resin bed? I get that it disturbs resolution.. but I'm not sure exactly what to say.

Chemistry
A portable electric water heater transfers 255 watts (W) of power to 5.5 L of water, where 1 W = 1 J/s. How much time (in minutes) will it take for the water heater to heat the 5.5 L of water from 25 degrees celsius to 42 degrees celsius? (Assume that the water has a density o...

Chemistry
25.0 mL of ethanol (density = 0.789 g/mL) initially at 7.0 degrees celsius is mixed with 35.0 mL of water (density = 1.0 g/mL) initially at 25.3 degrees celsius in an insulated beaker. Assuming that no heat is lost, what is the final temperature of the mixture?

Algebra
1. First you need to find the slope of the original line you are given which is 3x + y = 6. The slope is -A/B so it is -3/1 or just -3, m = -3. 2. The slope of a line perpendicular is the negative reciprocal so the slope of the line perpendicular to the given line is 1/3. 3. U...

chemistry
Determine the theoretical and percent yield of hydrogen gas is 36 g of water undergoes electrolysis to produce hydrogen and oxygen and 3.8 g of hydrogen is collected.

Chemistry
How would you make 100mL of tartrate buffer, pH 3.5, from 0.100 M tartaric acid, 1M NaOH and deionized and distilled H2O? You need to consider the ionization of two the two acidic groups separately.

Chemisty
16.72g of sodium acetate trihydride (MW=136 g/mol) is dissolved in 100mL water. To this, 4.00g glacial acetic acid (Ka=2.2x10-5, MW=60.0 g/mol) is added, and distilled water is added to to the 500mL mark. Find the final pH and the molar concentration of the buffer.

Chemistry
How would you make 100mL of tartrate buffer, pH 3.5, from 0.100 M tartaric acid, 1M NaOH and deionized and distilled H2O? You need to consider the ionization of two the two acidic groups separately.

Geometry
PQR is congruent to DJE. complete the statement below PR is congruent to __, DJ is congruent to __ angle E is congruent to __ 1) PR is congruent to PQ, DJ is congruent to PQ, angle E is congruent to angle R 2) PR is congruent to DE, DJ is congruent to DR, angle E is congruent ...

Pages: <<Prev | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | Next>>

For Further Reading

Search
Members
Community