Answer:
mass of CO = 210.42 g
mass in three significant figures = 210. g
Explanation:
Given data:
mass of Fe2O3 = 0.400 Kg
mass of CO= ?
Solution:
chemical equation:
Fe2O3 + 3CO → 2Fe + 3CO2
Now we will calculate the molar mass of Fe2O3 and CO.
Molar mass of Fe2O3 = (55.845 × 2) + (16 × 3) = 159.69 g/mol
Molar mass of CO = 12+ 16 = 28 g/mol
now we will convert the kg of Fe2O3 in g.
mass of Fe2O3 = 0.400 kg × 1000 = 400 g
number of moles of Fe2O3 = 400 g/ 159.69 g/mol = 2.505 mol
mass of CO = moles of Fe2O3 × 3( molar mass of CO)
mass of CO = 2.505 mol × 84 g/mol
mass of CO = 210.42 g
mass in three significant figures = 210. g
Answer:

Explanation:
To solve this problem, we can use the Combined Gas Laws:

Data:
p₁ = 1.7 kPa; V₁ = 7.5 m³; T₁ = -10 °C
p₂ = ?; V₂ = 3.8 m³; T₂ = 200 K
Calculations:
(a) Convert temperature to kelvins
T₁ = (-10 + 273.15) K = 263.15 K
(b) Calculate the pressure

Q1. Chemical, Physical, Physical, Physical
(l am not 100% sure about the 4th answer)
Q2. All of the above
Answer:
phosphorous- 5
calcium- 2
nitrogen- 3 or 5
iron- 8 (transition metals use subshells as valence electrons)
argon- 8
potassium- 1
helium- 2
magnesium- 2
sulfur- 6
lithium- 1
iodine- 7
oxygen- 6
barium- 2
aluminum- 3
hydrogen- 1
xenon- 8
copper- 1
Source: my own chemistry notes
Answer:
Well, one is if heat is absorbed by the system from the surroundings, the system gains heat from the surroundings and so the temperature of the surroundings decreases.
Explanation: