Answer:
We'll have 8.0 moles Fe3O4 and 4.0 moles CO2
Explanation:
Step 1: data given
Number of moles Fe2O3 = 12.0 moles
Number of moles CO = 12.0 moles
Step 2: The balanced equation
3Fe2O3 +CO → 2Fe3O4 + CO2
Step 3: Calculate the limiting reactant
For 3 moles Fe2O3 we need 1 mol CO to produce 2 moles Fe3O4 and 1 mol CO2
Fe2O3 is the limiting reactant. It will completely be consumed (12.0 moles).
CO is in excess. There will react 12.0 / 3 = 4.0 moles
There will remain 12.0 - 4.0 = 8.0 moles
Step 4: Calculate moles products
For 3 moles Fe2O3 we need 1 mol CO to produce 2 moles Fe3O4 and 1 mol CO2
For 12.0 moles Fe2O3 we'll have 2/3 * 12.0 = 8.0 moles Fe3O4
For 12.0 moles Fe2O3 we'll have 12.0 / 3 = 4.0 moles CO2
We'll have 8.0 moles Fe3O4 and 4.0 moles CO2
Answer:
0.342 m
Explanation:
From the question given above, the following data were obtained:
Mass of NaBr = 14.57 g
Mass of water = 415 g
Molar mass of NaBr = 102.89 g/mol
Molality of NaBr =?
Next, we shall determine the number of mole in 14.57 g of NaBr. This can be obtained as follow:
Mass of NaBr = 14.57 g
Molar mass of NaBr = 102.89 g/mol
Mole of NaBr =?
Mole = mass / molar mass
Mole of NaBr = 14.57 / 102.89
Mole of NaBr = 0.142 mole
Next, we shall convert 415 g of water to kg. This can be obtained as follow:
1000 g = 1 Kg
Therefore,
415 g = 415 g × 1 Kg / 1000 g
415 g = 0.415 Kg
Thus, 415 g is equivalent to 0.415 Kg.
Finally, we shall determine Molality of the solution as follow:
Mole of NaBr = 0.142 mole
Mass of water = 0.415 Kg
Molality of NaBr =?
Molality = mole / mass of water in Kg
Molality of NaBr = 0.142 / 0.415
Molality of NaBr = 0.342 m
Therefore, the molality of NaBr solution is 0.342 m.
<span>Although
the Statue of Liberty is made of copper (originally an orange-brown
color), it is green because the copper has interacted with substances in
the air to form new substances with different properties. This is an
example of a B. chemical change.
That is because chemical change occurs when certain substances change their properties when they interact with other substances. This is why the color of copper changed, while its physical properties stayed the same.
</span>
Answer:
In homeothermic (“warm-blooded”) animals, body temperature is carefully
regulated. The hypothalamus, located in the brain, acts as the master ther-
mostat to keep body temperature constant to within a fraction of a degree
Celsius in a healthy animal. If the body temperature starts to deviate much
from the desired constant level, the hypothalamus causes changes in blood
flow and initiates other processes, such as shivering or perspiration, to bring
the temperature back to normal. What evolutionary advantage does a con-
stant body temperature give the homeotherms (e.g., birds and mammals)
over the poikilotherms (e.g., reptiles and insects), whose body temperatures
are not kept constant? What are the disadvantages?
Explanation: Basic chemical understanding as revealed upwards
