Answer:
8.31 × 10⁻²² kJ
Explanation:
Step 1: Given data
Energy required to remove one mole of electrons from the atoms at the surface of a solid metal: 500 kJ/mol e⁻
Step 2: Calculate how much energy does it take to remove a single electron from an atom at the surface of this solid metal
We will use Avogadro's number: there are 6.02 × 10²³ electrons in 1 mole of electrons.
500 kJ/mol e⁻ × 1 mol e⁻/6.02 × 10²³ e⁻ = 8.31 × 10⁻²² kJ/e⁻
Answer and Explanation:
The steam of bubbles moves away from the stainless steel screw in the salt solution because in salt solution the molecules of the salts break down in ion form and produce electricity.
The electricity produced by the salt ion is responsible for the movement of bubbles
On the other hand in the solution of sugar no ions are produced and hence no electricity is generated and hence no movement of bubbles.
Answer:
For ²⁰⁸Pb²⁺ cation, the sum of the number of neutrons and electrons = 206
Explanation:
Lead, chemical symbol Pb, is a chemical element which belongs to the group 14 of the periodic table. The atomic number of lead is 82 and it is a member of the p-block.
The isotope of lead with the mass number 208, has 126 neutrons.
Since, atomic number = number of protons = number of electrons for neutral atom
Therefore, for ²⁰⁸Pb: number of electrons= 82
So, <u>for ²⁰⁸Pb²⁺ cation: number of electrons</u>= 82 - 2 = 80
<u>Therefore, for ²⁰⁸Pb²⁺ cation, the sum of the number of neutrons and electrons = number of electrons + number of neutrons = 80 electrons + 126 neutrons = 206.</u>
The unit of 16.8 /kjg contains a mistake.
I just can help you by assuming the right units.
I will assume 16.8 kj /g. This is a rate, which means that 1 g of reactant will produce 16.8 kj of heat.
To calculate the mass of reactant that will produce 800j first you multiply by the conversion factor to obtain kj, and the you divide by the rate of heat, 16.8 kj/g
heat * conversion factor / rate
(800j) * (1kj/1000j) / (16.8 kj / g) <--- answer
Answer:
-2,438 J energy is released
Heat energy is released
Explanation:
The formula for energy absorbed or released is Q = mT(Cp)
Get temperature in degrees T = 21 - 63 = -42°C
Mass of the cooling cooper m = 150g
Specific heat of copper Cp = 0.387J/g-°C
Put all the above parameters into the formula for energy absorbed or released
Q = mT(Cp)
= 150 x -42(0.387)
= -2438J same as -2.438 KJ
-2438J energy is released