Answer:
15.9 grams of copper is produced
Explanation:
Step 1: Data given
Volume of hydrogen = 5.60 L ( at STP)
Step 2: The balanced equation
CuO (s) + H2 (g) → Cu (s) + H2O (g)
Step 3: Calculate moles H2
22.4 L = 1 mol
5.60 L = 0.25 moles
Step 3: Calculate moles Cu
For 1 mol CuO we need 1 mol H2 to produce 1 mol Cu and 1 mol H2O
For 0.25 moles H2 we'll have 0.25 moles Cu
Step 4: Calculate mass Cu
Mass Cu = moles Cu * molar mass Cu
Mass Cu = 0.25 moles * 63.546 g/mol
Mass Cu = 15.9 grams
15.9 grams of copper is produced
Answer:
A
Explanation:
that should be the answer
Try 0.80 grams NaOH . M=mol/L if you rework it to get mol, you have mol=0.20M×0.100L which is 0.02mol of NaOH, multiply that by the amu of NaOH (39.998) and should get 0.799g
To solve this question, we will simply use the gas law which is as follows:
PV = nRT where:
P is the pressure = 100 kPa = 0.986923 atm
V is the volume = 6.8 liters
n is the required number of moles
R is the gas constant = 0.08206
T is the temperature = 25 degree celcius (room temp) = <span>298 kelvin
Substitute in the above equation to get the number of moles as follows:
</span> 0.986923 x 6.8 = n x 0.08206 x 298
n = 0.2744 moles
Answer: D.neither physically nor chemically changed.
Explanation:
A physical change is defined as a change in which there is alteration in shape, size etc. No new substance gets formed in these reactions.
Example: Melting of ice
A chemical change is defined as a change in which a change in chemical composition takes place. A new substance is formed in these reactions.
Example: Corrosion of iron
As the inside of the nail was still shiny and in same phase, that means it has not undergone any physical or chemical change.