294 Answered Questions for the topic Chemistry Lab

Recrystallization problem! ORGANIC CHEMISTRY

200 mg of impure sucrose was weighed out. After recrystallization from water, 225 mg of solid compound was obtained. What happened? How can this be corrected?
Chemistry Lab

09/24/17

toad, has a mass of 13.6 kg. Trevor jumps into a large cylinder containing water. The water level rises 2.50 L. What is the density of the toad?

What is the density of the toad?Express your answer in kg/L.
Chemistry Lab Chemistry Calcium Oxalate

09/24/17

why the change in the calcium oxalate equilibrium is produced?

We hace experimented with calcium oxalate and i have some observations that could help: First, we made a solution with 5mL of calcium chloride 0,1 M and 5 mL of sodium oxalate 0,1 M. this solution... more
Chemistry Lab

09/18/17

what percentage of the mixture is a salicylic acid if 1.94 g of the acid was isolated from 12.1 g of the mixture?

find the percentage
Chemistry Lab

09/17/17

What is the concentration

What is the concentration (in mol L-1) of 12.5 mg of each of disopyramide phosphate and lidocaine hydrochloride dissolved in 250 mL?
Chemistry Lab

09/17/17

Chemistry question

If 20 mg of a drug is dissolved in 250 mL of solvent, how many mg of the drug are present in 5 mL of that solution?
Chemistry Lab Chemistry

09/16/17

Possible Freezing Point Measurement Error

The freezing point of pure water was measured to be 0.18 to 0.20 degrees Celsius, The accepted freezing point of water is 0 degrees Celsius. What possible reasons could be the why I got this error... more
Chemistry Lab

09/14/17

determine the volume of 1.0 teaspoon. 1 tablespoon=3teaspoons; 1tablespoon=1/2 fluid ounce

question #3 on pg49 of chemistry lab book 
Chemistry Lab

09/11/17

Calculate required volume...

Calculate the required volume of Stock 2 (20 mg/mL of ethanol) that you will need to add to each of five volumetric flasks so that when diluted to 100 mL each will yield the desired ethanol... more
Chemistry Lab

09/10/17

Chemistry question

If a standard drink is defined as 10 g of alcohol, what volume of 38 % vodka corresponds to 1 standard drink? How many standard drinks are them in 150 mL of 8.8 % Sauvignon Blanc?
Chemistry Lab

09/10/17

Chemistry question calculation

If you are provided a stock solution of 15 mg/L of ethanol how much of this solution would you need to transfer to a 50 mL volumetric flask to produce a solution of concentration 1 mg/L?
Chemistry Lab

09/08/17

GC-MS analysis

What do you need to screen anabolic androgenic steroids in a single GC-MS analysis?
Chemistry Lab

09/05/17

When using a Bunsen burner and ring clamp, always use the "Three Finger Rule". Explain why this rule exists.

When using a Bunsen burner and ring clamp, always use the "Three Finger Rule". Explain why this rule exists.

multiple choice HCL + carbonate/nitrate question

31 A mixture of solids is treated with an excess of dilute hydrochloric acid. A colourless gas is evolved and a white precipitate forms. What are the solids in the mixture?   A calcium carbonate... more
Chemistry Lab

08/27/17

When a student was making his volumetric solution using the 100 ml volumetric flask, he filled the flask past the mark.

a) How would this affect the molarity of his solutions? e.g. would the actual molarity be higher or lower than the calculated molarity? Explain. b) How would this affect the density of his... more

Sodium benzoate in carbonated beverages

Sodium benzoate is a common food preservative and can be commonly found in the ingredient list of carbonated beverages. Carbonated beverages also contain phosphoric acid and are highly acidic.... more

Write a balanced equation

What would be the balanced equation for the synthesis of benzoic acid using the Gignard reagent, phenylmagnesium bromide? 
Chemistry Lab Science Chemistry Water

08/06/17

how to calculat temporary hardness water and permanent hardness of water and total hardness and normality can anyone help me to find solution

how to find hardness of water and normality in calculation

08/05/17

Percent yield/ Theoretical Yield

I was trying to figure out the limiting reagent of a reaction that I did in lab. The reaction is 1-phenyl ethanol that is oxidized to acetophenone using (5% aq. NaOCl (2.2 equiv)) and (HOAc (15M)).... more

07/08/17

Soil Lab (trace metals)

How would I calculate the amount of each metal in my groups sample? And how do I make the values I calculate are expressed in terms of amount of metal per amount of soil? &My final answers are... more
Chemistry Lab

07/07/17

How you would construct a heat pack using salt, water, and inexpensive materials (such as might be provided to you in lab)?

 The salt that is being used is CaCl2  
Chemistry Lab Chemistry

05/24/17

How many grams of copper would you expect to form from 34.0g of Fe?

theretical yeild
Chemistry Lab

05/23/17

meaning of literature value with respect to the question in the description.

"comment on the accuracy of your boiling point determination for theunknown liquid based on your observation in comparison with the literature value" What does this mean???

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