G A chemistry student needs of thiophene for an experiment. She has available of a w/w solution of thiophene in benzene. Calculate the mass of solution the student should use. If there's not enough solution, press the "No solution" button. Round your answer to significant digits.

The given question is not complete, the complete question is:

A chemistry student needs 5.00 g of thiophene for an experiment. She has available 0.50 kg of a 28.7% w/w solution of thiophene in benzene, Calculate the mass of solution the student should use. If there's not enough solution, press the "No solution" button Be sure your answer has the correct number of significant digits. X

The correct answer is 17.4 grams.

Explanation:

As mentioned in the given question, 28.7 percent w/w solution thiophene in benzene shows that,  

(wt. of thiophene / wt. of thiopene + benzene) * 100 = 28.7

0.50 kg of the solution indicates that it is 500 grams of the solution.  

Therefore, the amount of thiophene found in the 500 grams of the solution is,  

500 g * 28.7 / 100 = 143.5 gm

Thus, 143.5 grams of thiophene is found 500 grams of the solution.  

Now, 1 gram of thiophene will be in 500/143.5 of solution.  

Therefore, 5 grams of thiophene will be in 500/143.5 * 5 g of the solution = 17.42 grams of the solution.  

Hence, the mass of the solution to be used by the student in the given case will be 17.4 grams.  

a saline water is fed to a reverse osmosis unit at flow rate o rotameter connected to reject (retentate) line reads 8 installed in reject and permeate line reads 15.2 milli siemens/cm and 300 micro siemens/com respectively.

answer : one can design an experiment using a liquid and an additive that can be added to the liquid and observe the chemical changes in the reaction species.

one would need a beaker which is filled with a known amount of the liquid in which thermometer is placed to measure the temperature changes; after addition of the additive to the liquid solution one can note down the temperature change and find whether the reaction is endothermic or exothermic in nature. by subtracting the initial temperature value with the final temperature one can find the temperature changes.

various combinations of liquid and additive can be used. liquid in this case can be a known quantity of water and additives can be epsom salt or without epsom salt the experiment can be conducted to notice the changes. water and ice, hydrogen peroxide and dry yeast, vinegar and baking soda,etc.