Answer:
Mass = 84.82 g
Explanation:
Given data:
Number of molecules of CaSO₄ = 3.75× 10²³
Mass in gram = ?
Solution:
Avogadro number:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
1 mole = 6.022 × 10²³ molecules
3.75× 10²³ molecule × 1 mol / 6.022 × 10²³ molecules
0.623 mol
Mass in gram:
Mass = number of moles × molar mass
Mass = 0.623 mol × 136.14 g/mol
Mass = 84.82 g
Answer:
Mg would blow off. AI would be affective to copper but not to MG
Explanation:
The ideal gas equation is;
PV = nRT; therefore making P the subject we get;
P = nRT/V
The total number of moles is 0.125 + 0.125 = 0.250 moles
Temperature in kelvin = 273.15 + 18 = 291.15 K
PV = nRT
P = (0.250 × 0.0821 )× 291.15 K ÷ (7.50 L) = 0.796 atm
Thus, the pressure in the container will be 0.796 atm
Answer:
Redox type
Explanation:
The reaction is:
2Cr + 3Fe(NO₃)₂ → 2Fe + 2Cr(NO₃)₃
2 moles of chromium can react to 3 moles of iron (II) nitrate in order to produce 2 moles of iron and 2 moles of chromium nitrate.
If we see oxidation state, we see that chromium changes from 0 to +3
Iron changed the oxidation state from +2 to 0
Remember that elements at ground state has 0, as oxidation state.
Iron is being reduced while chromium is oxidized. Then, the half reactions are:
Fe²⁺ + 2e⁻ ⇄ Fe (Reduction)
Cr ⇄ Cr³⁺ + 3e⁻ (Oxidation)
When an element is being reduced, while another is being oxidized, we are in prescence of a redox reaction.
Answer:
C. 0.04 moles per cubic decimeter.
Explanation:
The molar mass of the Iodine is 253.809 grams per mole and a cubic decimeter equals 1000 cubic centimeters. The concentration of Iodine (
), measured in moles per cubic decimeter, can be determined by the following formula:
(1)
Where:
- Mass of iodine, measured in grams.
- Molar mass of iodine, measured in grams per mol.
- Volume of solution, measured in cubic decimeters.
If we know that 
, 
and 
, then the concentration of iodine in a solution is:
Hence, the correct answer is C.
