Answer:
The yield is 20 %.
Explanation:
Mg + 2 HCl → MgCl2 + H2
(12 g Mg) / (24.30506 g Mg/mol) x (1 mol H2 / 1 mol Mg) x (2.015894 g H2/mol) = 0.9953 g H2.
(0.2 g) / (0.9953 g) = 0.20 = 20% yield
Approximately, 21 kJ was released from the combustion of the 1-g sample.
<h3>
Define Heat. What is the SI unit of Heat?</h3>
Because heat is a type of energy, the SI unit for heat is also joules (J), which is defined as the quantity of energy required to increase the temperature of a given mass by one degree. This is significant because heat is a form of energy. Heat is the result of the movement of kinetic energy within a material or an item, or from an energy source to a material or an object. Radiation, conduction, and convection are the three mechanisms through which such energy can be transferred. The joule is the S.I. unit for heat.
To learn more about Joule, visit:
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Answer: The percent by volume of isopropyl alcohol in a solution made by mixing 120 mL of the alcohol with enough water to make 350 mL of solution is 25.5%.
Explanation:
Given: Volume of solute = 120 mL
Volume of solvent = 350 mL
Now, total volume of the solution is as follows.

Let us assume that 100 mL of solution is taken and the amount of isopropyl alcohol present in it is as follows.

Hence, there is 25.53 mL isopropyl alcohol is present in 100 mL of solution. Therefore, %v/v is calculated as follows.

Thus, we can conclude that the percent by volume of isopropyl alcohol in a solution made by mixing 120 mL of the alcohol with enough water to make 350 mL of solution is 25.5%.
Answer:
4.8 %
Explanation:
We are asked the concentration in % by mass, given the molarity of the solution and its density.
0.8 molar solution means that we have 0.80 moles of acetic acid in 1 liter of solution. If we convert the moles of acetic acid to grams, and the 1 liter solution to grams, since we are given the density of solution, we will have the values necessary to calculate the % by mass:
MW acetic acid = 60.0 g/mol
mass acetic acid (the solute) = 0.80 mol x 60 g / mol = 48.00 g
mass of solution = 1000 cm³ x 1.010 g/ cm³ (1l= 1000 cm³)
= 1010 g
% (by mass) = 48.00 g/ 1010 g x 100 = 4.8 %