Answer:
[Au] = 0.171 M
Explanation:
For this question, we assume the rock is 100 % gold.
First of all, we determine the moles of gold
67.3 g . 1mol/ 196.97g = 0.342 moles
Molar concentration is defined as the moles of solute, contained in 1L of solution.
Our solution volume is 2L.
M = 0.342 mol / 2L = 0.171
Molar concentration, also called molarity of solution is the most typical unit of concentration.
Answer: There are now 2.07 moles of gas in the flask.
Explanation:
P= Pressure of the gas = 697 mmHg = 0.92 atm (760 mmHg= 1 atm)
V= Volume of gas = volume of container = ?
n = number of moles = 1.9
T = Temperature of the gas = 21°C=(21+273)K= 294 K (0°C = 273 K)
R= Value of gas constant = 0.0821 Latm\K mol
When more gas is added to the flask. The new pressure is 775 mm Hg and the temperature is now 26 °C, but the volume remains same.Thus again using ideal gas equation to find number of moles.
P= Pressure of the gas = 775 mmHg = 1.02 atm (760 mmHg= 1 atm)
V= Volume of gas = volume of container = 49.8 L
n = number of moles = ?
T = Temperature of the gas = 26°C=(26+273)K= 299 K (0°C = 273 K)
R= Value of gas constant = 0.0821 Latm\K mol
Thus the now the container contains 2.07 moles.
Answer: Option (A) is the correct answer.
Explanation:
Atomic number of sodium is 11 and its electronic configuration is
.
In order to gain stability, sodium loses one electron and hence it forms a positive ion
.
Thus, we can conclude that when sodium combines with chlorine, it has a net charge of +1 because sodium loses a negative electron when forming chemical bonds.