First calculate for the molar mass of the given formula unit, CaCO₃. This can be done by adding up the product when the number of atom is multiplied to its individual molar mass as shown below.
molar mass of CaCO₃ = (1 mol Ca)(40 g Ca/mol Ca) + (1 mol C)(12 g of C/1 mol of C) + (3 mols of O)(16 g O/1 mol O) = 100 g/mol of CaCO₃
Then, divide the given amount of substance by the calculated molar mass.
number of moles = (20 g)(1 mol of CaCO₃/100 g)
number of moles = 0.2 moles of CaCO₃
<em>Answer: 0.2 moles</em>
Answer: B) It presents the correct sequence of events in Earth’s history.
Explanation: edge 2021
For this system, we use Dalton's law of partial pressures where the total pressure of a gas mixture is said to be equal to the sum of the partial pressures of the gases. The partial pressure of each gas would be calculated by the product of the mole fraction and the original pressure of the gas. We do as follows:
Total pressure = x1P1 + x2P2
Total pressure = (2.0 / 7.0 )(3.5) + (1.5/7.0)(2.6)
Total pressure = 1.56 atm
Answer: D. test tubes, thermometers, etc
I think this is the correct answer. Sorry if it is not.
Explanation:
