Answer:
Gneiss forms by regional metamorphism from both high temperature and pressure. Quartzite and marble are the most commonly used metamorphic rocks.
Answer:
14.336 g MnF₂
Explanation:
number of moles = mass / molecular weight
number of moles of MnI₂ = 55 / 309 = 0.178 moles
number of moles of F₂ = 55 / 38 = 1.447 moles
From the reaction and the number of moles calculated we deduce that the fluorine F₂ is a limiting reactant.
So:
if 13 moles of F₂ reacts to produce 2 moles of MnF₃
then 1.447 moles of F₂ reacts to produce X moles of MnF₃
X = (1.447 × 2) / 13 = 0.223 moles of MnF₃ (100% yield)
For 57.2% yield we have:
number of moles of MnF₃ = (57.2 / 100) × 0.223 = 0.128 moles
mass = number of moles × molecular weight
mass of MnF₃ = 0.128 × 112 = 14.336 g
Answer: Manholes are usually round, primarily because roundness is the best shape to resist the compression of the earth; covers are round because they are easier to manufacture than square or rectangular shapes, they are easier to move by rolling, and they can't fall into the opening.
Explanation:
