40.0 g ( 1 mole ) --------------- 6.02x10²³ molecules
? ? --------------------------- 2.90x10²² molecules
mass = 2.90x10²² * 40.0 / 6.02x10²³
mass = 1.16x10²⁴ / 6.02x10²³
mass = 1.9269 g
hope this helps!
Answer:
H₂SO₄ (aq) + 2LiOH (aq) ⇒ Li₂SO₄ (aq) + 2H₂O (l)
Explanation:
This is an acid-base reaction, so we know the products are going to a salt/ionic compound and water.
Answer:
The Lewis structures are shown in the figure
Explanation:
The lewis structure will be drawn using following steps
i) we will calculate the total number of valence electrons in the molecule
ii) will assign one bond (two electrons in between two atoms)
iii) then distribute the rest of the valence electrons as lone pair or shared pair based on completion of octet.
The structure of each molecule is given in the figure.
Valence electrons:

V.E = 5 +(2)6-1=16

V.E =5 +(2)6+7=24
Answer: 83%
Explanation:
The detailed solution is shown in the image attached. First we must work out the balanced reaction equation because accurate solution of the problem must be based on the stoichiometry of the reaction. From the given concentration and volume of reactants, we calculate the amount of substance reacted hence identify the limiting reactant. Lastly we use simple proportion to obtain the theoretical yield of the precipitate. This is now used to calculate the actual yield as shown in the solution attached.
Answer:
we will use the Clausius-Clapeyron equation to estimate the vapour pressures of the boiling ethanol at sea level pressure of 760mmHg:
ln (P2/P1) =
-
)
where
P1 and P2 are the vapour pressures at temperatures T1 and T2
Δ
vapH = the enthalpy of vaporization of the ETHANOL
R = the Universal Gas Constant
In this problem,
P
1
=
100 mmHg
; T
1
=
34.7 °C
=
307.07 K
P
2
=
760mmHg
T
2
=T⁻²=?
Δ
vap
H
=
38.6 kJ/mol
R
=
0.008314 kJ⋅K
-1
mol
-1
ln
(
760/10)=(0.00325 - T⁻²) (38.6kJ⋅mol-1
/0.008314
)
0.0004368=(0.00325 - T⁻²)
T⁻²=0.002813
T² = 355.47K