1. Magnesium atoms also have a slightly smaller radius than sodium atoms, and so the delocalised electrons are closer to the nuclei.
2. Sodium has higher melting point than potassium because of stronger metallic bonding .
3. Potassium are very soft metal can be very easily cut with a knife
4. Increase of resistance in metals. Therefore the mobility of electrons decreases and causes decrease in conductivity.
5.To increase strength, increase corrosion resistance, or reduce costs.
6. All metals have low ionization energies and are relatively electropositive, and so they lose electrons fairly easily.
7. All the group 1 metals are reactive, but they get more reactive as you go down the group, so potassium is more reactive than sodium.
Answer:
1. 0.338 moles of Fe
2. 0.700 moles of Fe
3. 48.3%
Explanation:
This is the reaction:
Fe₂O₃ + 3C → 2Fe + 3CO
We were told that we produce 18.9 g of Fe. Let's convert the mass to moles:
18.9 g . 1mol/ 55.85 g = 0.338 moles of Fe
Let's make a rule of three; ratio is 1:2.
1 mol of oxide can produce 2 moles of elemental iron
Then, 0.350 moles must produce (0.350 .2) / 1 = 0.700 moles of Fe
Let's determine the percent yield:
(Yield produced /Theoretical Yield) . 100 = 48.3 %
According to the reaction equation:
CH3COO- + H+ → CH3COOH
initial 0.25 0.15
change - 0.025 + 0.025
Equ (0.25-0.025) (0.15 + 0.025)
first, we have to get moles acetate and moles acetic acid:
moles of acetate = 0.25 - 0.025 = 0.225 moles
∴ [CH3COO-] = 0.225 mol / 1 L = 0.225 M
moles of acetic acid = 0.15 + 0.025 = 0.175 moles
∴ [ CH3COOH] = 0.175 mol / 1L = 0.175 M
Pka = -㏒ Ka
= -㏒ 1.8 x 10^-5
= 4.74
from H-H equation we can get the PH value:
PH = Pka + ㏒ [acetate / acetic acid]
PH = 4.74 + ㏒[0.225/0.175]
∴ PH = 4.8
Answer:
The answer is <em><u>true</u></em> NOT false
