Answer:
Mass = 114.26 g
Explanation:
Given data:
Number of gold atoms = 3.47×10²³ atoms
Mass in gram = ?
Solution:
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 atoms
3.47×10²³ atoms × 1 mol /6.022 × 10²³ atoms
0.58 mol
Mass of gold:
Mass = number of moles × molar mass
Mass = 0.58 mol × 197 g/mol
Mass = 114.26 g
In order to solve this question, we must apply the conservation of mass. The total number of nucleons (upper number) and protons (lower number) must be equal before and after the decay. The new nucleon number is
218 - 4
= 214
And new proton number is
84 - 2
= 82
Next, we must identify which element has the proton number 82. That would be lead, Pb.
Therefore, the answer is
5. ²¹⁴Pb₈₂
Answer:
Group of highly-reactive chemical elements. The alkali metals are a group (column) in the periodic table consisting of the chemical elements lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr).
Answer:
0.825 M
Explanation:
The osmotic pressure is a colligative property, that can be calculated using the following expression.
π = M × R × T
where,
π is the osmotic pressure
M is the molarity
R is the ideal gas constant
T is the absolute temperature (24°C + 273 = 297 K)
M = π / R × T = 20.1 atm / (0.08206 atm.L/mol.K) × 297 K = 0.825 M
Answer:
gaseous CO2 bubbles out of the solution
Explanation:
We already know that the dissolution of a gas in water is exothermic. Hence, when the temperature of a solution containing a gas is increased, the solubility of the gas decreases and the gas bubbles out of the solution.
Similarly, the dissolution of KNO3 in water is endothermic. This implies that the solubility of the solid increases with increasing temperature.
Thus the solid becomes more soluble at 75°.
