Answer: The volume of 0.640 grams of
gas at Standard Temperature and Pressure (STP) is 0.449 L.
Explanation:
Given: Mass of
gas = 0.640 g
Pressure = 1.0 atm
Temperature = 273 K
As number of moles is the mass of substance divided by its molar mass.
So, moles of
(molar mass = 32.0 g/mol) is as follows.

Now, ideal gas equation is used to calculate the volume as follows.
PV = nRT
where,
P = pressure
V = volume
n = no. of moles
R = gas constant = 0.0821 L atm/mol K
T = temperature
Substitute the values into above formula as follows.

Thus, we can conclude that the volume of 0.640 grams of
gas at Standard Temperature and Pressure (STP) is 0.449 L.
Answer:
A)
<u>4, 7, 4, 6</u>
B)
<u>12 moles</u>
Explanation:

__↑______↑
8.00 mol | 14.00 mol
________________

You can turn this into a system of variables which are solvable.
To do this, create variables for the coefficients of each compound in the reaction respectively.

Because to be balanced, the count of atoms in each element of the compound correspond to the coefficient of the variable in that compound so that the count of the left (reactant) side is set equal to the right (product) side.
a corresponds to the coefficient of the first compound, b corresponds to the coefficient of the second compound, c corresponds to the coefficient of the third compound, and d corresponds to the coefficient of the fourth compound.
(Reactant = Product)
Reactant: 1a [N] Product: 1c.
Reactant: 3a [H] Product: 2d.
Reactant: 2b [O] Product: 2c + 1d.
Thus the system is:
1a = 1c
3a = 2d
2b = 2c + 1d.
Then just use the substitution methods to solve.
Answer:
The standard enthalpy of formation of methanol is, -238.7 kJ/mole
Explanation:
The formation reaction of CH_3OH will be,

The intermediate balanced chemical reaction will be,
..[1]
..[2]
..[3]
Now we will reverse the reaction 3, multiply reaction 2 by 2 then adding all the equations, Using Hess's law:
We get :
..[1]
..[2]
[3]
The expression for enthalpy of formation of
will be,



The standard enthalpy of formation of methanol is, -238.7 kJ/mole
Answer:
Mass of sea food = 30.98 Kg
Mass of sea food in pound = 68.31 lbs
Explanation:
Salmon, crab and oysters all are sea food.
Mass of sea food = Mass of salmon + Mass of crab + mass of oyster
Mass of salmon = 22 kg
Mass of crab = 5.5 kg
Mass of oysters = 3.48 kg
Mass of sea food = Mass of salmon + Mass of crab + mass of oyster
= 22 + 5.5 + 3.48
= 30.98 Kg
1 Kg = 2.205 lbs
Therefore, 30.98 kg = 30.98 × 2.205
= 68.31 lbs