1) Chemical reaction:
Fe2O3 + 2Al ---> Al2O3 + 2Fe
2) molar ratios
1 mol Fe2O3 : 2Al : 1 mol Al2O3 : 2 mol Fe
3) Convert 15.0 g of iron into moles
atomic mass Fe = 55.8 g/mol
moles = mass in grams / atomic mass = 15.0 g / 55.8 g/mol = 0.269 mol
4) Use proportions to determine the moles of Fe2O3, Al, and Al2O3
a) 1mol Fe2O3 / 2 mol Fe = x / 0.269 mol Fe
x =
=> x = 0.269 mol Fe * 1 mol Fe2O3 / 2 mol Fe = 0.134 mol Fe2O3
b) 2 mol Al / 2 mol Fe = x / 0.269 mol Fe
=> x = 0.269 mol Al
c) 2 mol Fe / 1 mol Al2O3 = 0.269 mol Fe / x
=> x = 0.269 mol Fe * 1 mol Al2O3 / 2 mol Fe
x = 0.134 mol Al2O3
5) Convert moles to grams
a) Fe2O3
molar mass Fe2O3 = 2* 55.8 g/mol + 3*16g/mol = 159.6 g/mol
mass = molar mass * number of moles
mass = 159.6 g/mol * 0.134 mol = 21.4 g
b) Al
atomic mass = 27.0 g/mol
mass = number of moles * atomic mass = 0.269 mol * 27.0 g/mol = 7.26 g
c) Al2O3
molar mass = 2 * 27.0 g/mol + 3*16.0 g/mol = 102.0g/mol
mass Al2O3 = numer of moles * molar mass = 0.134 mol * 102.0 g/mol = 13.7 g
Answers:
21.4 g Fe2O3
7.26 g Al
13.7 g Al2O3
Answer:
shivering
hair on the body standing up
goosebump forming
Explanation:
The processes that help the body warm-up from the available options include <em>the shivering of the body</em>, <em>formation of goosebumps on the skin</em>, and <em>the standing up of hairs on the body.</em>
When the temperature of the body falls below the setpoint or the environment is cold, a homeostatic response is triggered and a signal is sent from the control center to the muscles of the body. <u>The muscles start shaking in order to generate heat to raise the temperature of the body</u>. At the same time, <u>the tiny muscles at the base of the hairs on the skin contract and pull the hairs erect, causing goosebumps in the process.</u>
Answer:
.500
Explanation:
Use the ideal gas law equation: PV = nRT
Plug in the initial values given:
P = 1.2 atm
V = .500 L
n = number of moles
R = Gas Constant 8.314
T = 25.0 C
(1.2)(.5) = n(8.314)(25)
solving for n we get .00289
Now use the same equation with the new values solving for V
(3.6)V = (.00289)(8.314)(75.0)
V = .4999999 ROund to .500
Answer:
Explanation:
Data Given
Formula of hydrazine = N₂H₄
Lewis structure of hydrazine (N₂H₄) =?
Solution:
- Hydrazine (N₂H₄) contains 2 Nitrogen atoms and 4 Hydrogen atoms
- Nitrogen atom have 5 valence electrons
- Hydrogen have 1 valance electron
- So it have 14 total number of valance electrons
N₂ H₄ = 2 (5) + 4(1) = 14 no. o electrons
- it is a stable compound and obey octet rule for nitrogen and duplet rule for hydrogen by sharing of electrons.
To draw the Lewis Structure
- Put the 2 nitrogen in center and draw the Hydrogen on the outside
- Put the 2 hydrogen on out side of each of the nitrogen
- Then draw the 2, 2 valence electrons between atoms that form chemical bond
- So we will draw total 14 electrons in the structure
- then we count electrons around each atom of nitrogen and hydrogen that it have 8 and 2 electrons to complete its octet and duplet respectively
Lewis Structure of N₂ H₄ in attachment
