Answer:
For neutral atoms, the number of valence electrons is equal to the atom's main group number. The main group number for an element can be found from its column on the periodic table. For example, carbon is in group 4 and has 4 valence electrons. Oxygen is in group 6 and has 6 valence electrons.
Explanation:
Answer:
0.268 L
Explanation:
concentration is the number of moles of solute in 1 L of solution
number of moles of KCl - 5.0 g / 74.5 g/mol = 0.067 mol
the concentration of the solution to be prepared - 0.25 mol/L
concentration = number of moles of KCl / volume of solution
substituting the values in the equation
0.25 mol/L = 0.067 mol / V
V = 0.268 L
solution should be diluted to 268 mL to make a 0.25 M solution
Answer:
1 gram of H2 will be produced from 12 grams of Mg.
Explanation:
According to Stoichiometry, 0.5 moles of Mg are present. 1 mole of Mg produces 1 mole of H2, so 0.5 moles of Mg will produce 0.5 moles of H2. Multiplying molar mass of H2 i.e. 2 gram/mole with 0.5 moles, we can find the mass of H2 in grams which is 1 gram.
<u>Answer: </u>
The pressure of a sample of argon gas was increased from 2.12atm to 6.96atm at constant temperature. If the final volume of the argon sample was 16.9L
. The initial volume of the argon sample was 55.5L
<u>Explanation:</u>
Considering the initial volume, initial pressure to be V1 and P1 respectively
Assuming the final volume and final temperature of the gas to be V2 and P2 respectively
Given,
Pressure of the gas was increased from 2.12 atm to 6.96 atm
Therefore, P1 = 2.12 atm
P2 = 6.96 atm
Final volume, V2 = 16.9 L
Applying Boyle’s law,
Substituting the value
V1 = 55.5 L
Therefore, the initial volume was 55.5L