When you heated the can with the bit of water inside and you boiled it over a flame, the water turned to vapor (gas) and the pressure in the inside of the can is different from the pressure on the outside of the can. When you placed the can into a ice water beaker or a container, the can shrunk it's size, decreasing it's mass and density. The can shrunk as a result of the inside pressure being equalized with the outside pressure.
The part where you placed it in the ice bath or container was when the water vapor was forced out of the can.
Answer:
0.185M sulfuric acid
Explanation:
Based on the reaction:
H₂SO₄ + 2KOH → K₂SO₄ + 2H₂O
<em>1 mole of sulfuric acid reacts with 2 moles of KOH</em>
Initial moles of H₂SO₄ and KOH are:
H₂SO₄: 0.750L ₓ (0.470mol / L) = <em>0.3525 moles of H₂SO₄</em>
KOH: 0.700L ₓ (0.240mol / L) = <em>0.168 moles of KOH</em>
The moles of sulfuric acis that react with KOH are:
0.168mol KOH ₓ (1 mole H₂SO₄ / 2 moles KOH) = 0.0840 moles of sulfuric acid.
Thus, moles that remain are:
0.3525moles - 0.0840 moles = <em>0.2685 moles of sulfuric acid remains</em>
As total volume is 0.700L + 0.750L = 1.450L, concentration is:
0.2685mol / 1.450L = <em>0.185M sulfuric acid</em>
Answer:
n = 7.86 mol
Explanation:
This question can be solved using the ideal gas law of PV = nRT.
Temperature must be in K, so we will convert 22.5C to 295 K ( Kelvin = C + 273).
R is the ideal gas constant of 0.0821.
(2.24atm)(85.0L) = n(0.0821)(295K)
Isolate n to get:
n = (2.24atm)(85.0L)/(0.0821)(295K)
n = 7.86 mol
Group 6 elements usually have extra electrons to make give them an octet. So, they have 6 electrons to start and when they have an octet, they have 8.
We can find the charge by doing simple math 6 - 8 = -2
Answer is D)
