A. Crust B. Mantle C. Outer Core D. Inner Core, i just studied that
Answer:
72.57 grams
Explanation:
The mass percentage of gold in the ore is 0.19 %
The mass of ore used = 23 kg
The mass of gold in the ore = 
moles of gold in the given mass of ore =
As per given equation four moles of Au is giving four moles of complex compound on reacting with NaCN
Then in second reaction two moles of the complex is reacting with one mole of Zinc
Thus two moles of gold are reacting with one mole of Zinc
The moles of Zinc needed = 0.5 X 2.22 mol = 1.11 moles
The mass of Zinc needed = moles X atomic mass =1.11 X 65.38 = 72.57 grams
It is a statement of fact. explains how energy is produced, and describes the behavior of energy.
Answer:
133.74 L
Explanation:
First we <u>convert the given pressures and temperatures into atm and K</u>, respectively:
- 750.0 Torr ⇒ 750/760 = 0.9868 atm
- 20°C ⇒ 20+273.16 = 293.16 K
- 40°C ⇒ 40+273.16 = 313.16 K
Then we<u> use the PV=nRT formula to calculate the number of moles of helium in the balloon</u>, using<em> the data of when it was on the ground</em>:
- 0.9868 atm * 8.50 L = n * 0.082 atm·L·mol⁻¹·K⁻¹ * 293.16 K
Then, knowing the value of n, we <u>use PV=nRT once again, this time to calculate V</u> using <em>the data of when the balloon was high up:</em>
- 0.550 atm * V = 2.866 mol * 0.082 atm·L·mol⁻¹·K⁻¹ * 313.16 K
Answer:
In the desert, the climate is hot and dry, while in the tundra, it is cold and wet.
Explanation:
in the desert, plants need more water, while in the tundra, they have ice and snow
