The moles of each element found in a 5.00 g nickel coin is calculated as below
moles =mass/molar mass
calculate the mass of each element =% composition of element/100 x total mass of nickel
Mn = 9/100 x5 = 0.45g
Cu=56/100 x5= 2.8 g
Ag= 35/100x5= 1.75 g
moles of each element is therefore=
Mn = 0.45g/54.94 = 8.19 x10^-3 moles
Ag=1.75g/107.87 g/mol = 0.0162 moles
Cu = 2.8 g/63.5 g/mol=0.0441 moles
Answer:
0.027g
Explanation:
From Avogadro's hypothesis, 1mole of any substance contains 6.02x10^23 molecules.
From the above, it means that 1mole of SO3 also contains 6.02x10^23 molecules.
1mole of SO3 = 32 + (16x3) = 32 + 48 = 80g
If 1 mole (80g) of SO3 contains 6.02x10^23 molecules,
Then Xg of SO3 will contain 2x10^20 molecules i.e
Xg of SO3 = (80x2x10^20)/6.02x10^23 = 0.027g
Answer:PH2=0.994atm, mass of zinc=0.606g
Explanation:
Equation for the reaction is written as;
Zn(s) + 2HCl(aq) - ZnCl2(aq) + H2(g)
V= 240ml = 0.240L
T= 30.8oC = 303.8K
Ptotal= 1.036atm
Pwater = 32mmHg at 30oC = 0.042atm
Therefore
PH2 = Ptotal - Pwater
= 1.036-0.042atm
=0.994atm
But PV= nRT
n = PV/RT
= 0.994x0.240/0.0821x303.8
= 0.24/24.94
=0.009324moles
For the grams of zinc
n=mass in grams/molar mass
Mass in grams = no of moles x molar mass
=0.009324x65 = 0.606g
