<span>The calculation of quantities in chemical equations are called Stoichiometry. Stoichiometry is a branch of chemistry which deals with relative quantities of reactants and products in chemical reactions. The correct answer is 'Stoichoimetry'. I hope this helps you. </span>
Answer:
(a) Ethyl acetate and hexane, and (c) methanol and methylene chloride.
Explanation:
re-crystallization is a technique used to purify solid compound. Ethyl acetate and hexane are good solvent pair for recrystallization because they are miscible with each other due to their good differences in polarity. ethyl acetate has polarity of 77 while hexane has 68.
water and diethyl ether are not good solvent pair for recrystallization because water and diethyl ether are immiscible. They have very far polarity values. water has 100 while diethyl ether has 35
The tubes 1, 5 and 6 is the answer to the question which test tubes were used to determine the optimal ph lipase activity. Lipase is an enzyme and optimum ph the maximum possible point on which enzyme become active.
The number of moles of ethanol the chemist will use in the experiment involving 30g of ethanol is 0.65moles.
<h3>How to calculate number of moles?</h3>
The number of moles of a substance can be calculated by dividing the mass of the substance by its molar mass. That is;
no. of moles = mass ÷ molar mass
According to this question, a chemist will use a sample of 30 g of ethanol (CH3CH2OH) in an experiment. The number of moles can be calculated as follows:
Molar mass of ethanol = 12(2) + 1(5) + 17 = 46g/mol
no of moles = 30g ÷ 46g/mol
no. of moles = 0.65moles
Therefore, the number of moles of ethanol the chemist will use in the experiment involving 30g of ethanol is 0.65moles.
Learn more about moles at: brainly.com/question/1458253
