Answer:
Law of Conservation of Energy
Explanation:
<h2>Phenocrysts and Porphyritic texture
</h2>
Explanation:
- The early formed crystals are of phenocrysts and the texture of these crystals is porphyritic texture.
- This crystallization occurs when early-forming plagioclase crystals which are rich in calcium start coating with plagioclase crystals which are rich in sodium.
- On cooling, the magma is then processed in a volcanic eruption, after the eruption the liquid which is left behind will start cooling and forms a porphyritic texture.
Answer:
Solution:
Here we have to calculate the mass .
It is known that mass = density volume.
(a) a sphere of gold with a radius of 10.0 cm [the volume of a sphere with a radius r is.
V = (4/3)πr3; the density of gold = 19.3 g/cm3]
In this question it has been given that,
Density = 19.3 g/cm3.
Explanation:
Answer:
B) Percent yield = 56%
Explanation:
Given data:
Mass of potassium iodide = 23 g
Mass of lead iodide formed = 18 g
Percent yield = ?
Solution:
Chemical equation:
2KI + Pb(NO₃)₂ → 2KNO₃ + PbI₂
Number of moles of potassium iodide:
Number of moles = mass / molar mass
Number of moles = 23 g/ 166 g/mol
Number of moles = 0.14 mol
Now we will compare the moles of PbI₂ and KI:
KI : PbI₂
2 : 1
0.14 : 1/2×0.14 = 0.07
Theoretical yield of PbI₂:
Mass = number of moles × molar mass
Mass = 0.07 × 461 g/mol
Mass = 32.27 g
Percent yield:
Percent yield = actual yield / theoretical yield × 100
Percent yield = 18 g/ 32.27 g × 100
Percent yield = 56%
I think it is correct......