Answer
512kj/mole
Explanation:
What is the work function of gold metal in kJ/mol if light with λ = 234 nm is necessary to eject electrons?
The energy can be calculated using below expresion;
E = hc/λ
Where h= planks constant= 6.626 x 10^-34
c= speed of light= 3 x 10^
λ= wavelength
hc= (6.626 x 10^-34 x 3 x 10^ 8)
=
Answer:
57.48%
Explanation:
Calculate the mass of 1 mole of malachite:
MM Cu = 63.55
MM O = 16.00
MM H = 1.01
MM C = 12.01
A mole of malachite has:
2 moles of Cu
5 moles of O
2 moles of H
1 mole of C
MW Malachite = 2*MM(CU) + 5*MM(O) + 2*MM(H) + 1 *MM(C)
MW Malachite = 2*63.55 + 5*16.00 + 2*1.01 + 1*12.01
MW Malachite = 221.13
Mass of Cu in a mole of Malachite = 2*MM(CU) = 127.1
Now divide the mass of Cu by the mass of Malachite
HCl is an acid, C5H5N is a base, Cl is an acid, and HC5H5N is an acid.
Hope this helps! If so, brainliest would be appreciated!
<span>Answer: an element and a compound.
An element is a pure substance formed by one kind of atoms (element).
A compound is a pure substance formed by several types of atoms(elements) that are connected by chemical bonds.
</span>
Answer:
The answer to your question is below
Explanation:
Trial 1 Trial 2
mass of Mg 0.255 g 0.353 g
mass of MgO 0.418 g 0.576 g
Chemical reaction
2Mg(s) + O₂(g) ⇒ 2MgO(s)
Question 1.
Atomic mass of Mg = 24.31 x 2 = 48.62 g
Molecular mass of MgO = 2(24.31 + 16) = 80.62 g
Trial 1
48.62 g of Mg ----------------- 80.62 g of MgO
0.255 g ---------------- x
x = (0.255 x 80.62)/48.62
x = 0.422 g of MgO
Trial 2 48.62 g of Mg ----------------- 80.62 g of MgO
0.353 g ---------------- x
x = (0.353 x 80.62)/48.62
x = 0.585 g of MgO
Question 2
Trial 1
Percent yield = 0.418/0.422 x 100 = 99%
Trial 2
Percent yield = 0.576/0.585 x 100 = 98.5%
Question 3
Average = (99 + 98.5)/2
= 98.75%
