While the crust of the Earth has been cooled down for millions of years, the inside is still hotter than the surface of the sun. The mantle that the tectonic plates are sitting on is constantly moving, causing the plates to move along with it. Basically the tectonic plates move around on the mantle like a beach ball does on water.
Answer:
D. The development of a solar heating system.
Explanation:
Warming a cup by adding hot tea is science, so is study of heat transfer so the answer has to be D
Answer : The pressure of the hydrogen gas exert before its volume was decreased will be, 2.28 atm
Explanation :
According to the Boyle's law, the pressure of the gas is inversely proportional to the volume of the gas at constant temperature of the gas and the number of moles of gas.
or,
or,
where,
= initial pressure of the gas = ?
= final pressure of the gas = 5.09 atm
= initial volume of the gas = 12.16 L
= final volume of the gas = 5.45 L
Now put all the given values in this formula, we get the initial pressure of the gas.
Therefore, the pressure of the hydrogen gas exert before its volume was decreased will be, 2.28 atm
Answer:
B. Cl.
Explanation:
These are Group 7 elements whose reactivity reduces as you go down the group. Chlorine has a smaller atoms than the rest and has a stronger tendency to grab an electron in its valency shell. This is because its nucleus is closer to the outer electrons than the other elements.
Answer:
The maximum number of moles of PH₃ that can be formed is 0.8 moles.
Explanation:
The balanced reaction is:
P₄ + 6 H₂ → 4 PH₃
By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of each compound participate in the reaction:
- P₄: 1 mole
- H₂: 6 moles
- PH₃: 4 moles
The limiting reagent is one that is consumed first in its entirety, determining the amount of product in the reaction. When the limiting reagent is finished, the chemical reaction will stop.
To determine the limiting reagent, you can use a simple rule of three as follows: If by stoichiometry of the reaction 6 moles of hydrogen react with 1 mole of phosphorus, 4 moles of hydrogen will react with how many moles of phosphorus?
moles of phosphorus= 0.667
But 0.667 moles of phosphorus are not available, 0.2 moles are available. Since you have less moles than you need to react with 4 moles of hydrogen, phosphorus will be the limiting reagent.
Then you can apply the following rule of three: if by stoichiometry 1 mole of P₄ forms 4 moles of PH₃, 0.2 moles of P₄ will form how many moles of PH₃?
moles of PH₃= 0.8
<u><em>The maximum number of moles of PH₃ that can be formed is 0.8 moles.
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