Answer:
V HCNsln = 0.9176 L
Explanation:
V HCNsln = ?
∴ m HCN = 31 g
∴ <em>C</em> HCNsln = 1.25 mol/L
∴ molar mass HCN = 27.0253 g/mol
⇒ V HCNsln = (31 g)*(mol/27.0253 g)*(L/1.25 mol) = 0.9176 Lsln
The greatest aqueous freezing point is (D) 0.10 KCI
Which list of elements contains a metal, a metalloid, and a nonmetal?(1) Zn, Ga, Ge (3) Cd, Sb, I(2) Si, Ge, Sn (4) F, Cl, Br
Sladkaya [172]
3) Cd . Sb . I
<span>look at the periodic chart- if the element is on the right it is a nonmetal, if it is on the left its a metal, and if it is in between it is a metalloid</span>
Answer:
Option D. 30 g
Explanation:
The balanced equation for the reaction is given below:
2Na + S —> Na₂S
Next, we shall determine the masses of Na and S that reacted from the balanced equation. This is can be obtained as:
Molar mass of Na = 23 g/mol
Mass of Na from the balanced equation = 2 × 23 = 46 g
Molar mass of S = 32 g/mol
Mass of S from the balanced equation = 1 × 32 = 32 g
SUMMARY:
From the balanced equation above,
46 g of Na reacted with 32 g of S.
Finally, we shall determine the mass sulphur, S needed to react with 43 g of sodium, Na. This can be obtained as follow:
From the balanced equation above,
46 g of Na reacted with 32 g of S.
Therefore, 43 g of Na will react with = (43 × 32)/46 = 30 g of S.
Thus, 30 g of S is needed for the reaction.
Answer:
Have the same number of electrons in their outer energy levels
Explanation:
Elements in the same group have similar chemical properties because they have the same number of valence electron(s) in their outermost shell.
Chlorine and Iodine have similar chemical properties because they have the same number of valence electron in their outermost shell. This can be seen from their electronic configuration as shown below:
Cl (17) => 1s² 2s²2p⁶ 3s²3p⁵
I (53) => [Kr] 4d¹⁰ 5s²5p⁵
From the above illustration:
Outer shell of Cl (3s²3p⁵) = 2 + 5 = 7 electrons
Outer shell of I (5s²5p⁵) = 2 + 5 = 7 electrons
Since they have the same number of valence electrons, therefore, they will have similar chemical properties.