The phrase 1 meter per second is a unit of velocity and is a unit of rate. 1 meter per second means for every second, for example, a man runs, he travels 1 meter distance. 1 meter per second is a derivative of the primary units of SI system, meter for distance and second for time.
The reaction is;
2Na + 2H2O → 2NaOH + H2
Answer:
4.4 × 10^(23) atoms
Explanation:
The reaction is;
2Na + 2H2O → 2NaOH + H2
2 moles of Na produces 1 mole of H2 from the equation reaction.
Thus, since 8.2 L of hydrogen gas at STP are produced. And we know that at STP, 1 mole of a gas will have a volume of 22.4 L, and also, We know according to avogadro's number that, 1 mol = 6.02 × 10^(23) atoms, Thus;
8.2 L of H2 × (1 mole of H2/22.4 L) × (2 mole of Na/1 mole of H2) × (6.02 × 10^(23) atoms/1 mole of Na) = 4.4 × 10^(23) atoms
The answer should be A, the number of electrons increases by 1, from left to right.
Across the periods (horizontal direction) in periodic table, each element has one more electron then the one before it. The number of period determines the number of occupied electron shells of the elements in that period. Which means, period 1 elements have 1 occupied electron shell, period 2 has 2, period 3 has 3 etc.
Therefore, the answer is A, we always go from left to right, and plus since period 2 elements only have 2 occupied electrons so their 2nd electron shell electrons must increase throughout the period.
Since there is no sample, let us assume 100 g of the solution:
(22.2% of 100 g) / (46.0254 g HCOOH/mol) = 0.48234 mol HCOOH
(100 g - 22.2 g) = 77.8 g = 0.0778 kg water
(0.48234 mol HCOOH) / (0.0778 kg) = 6.1997 mol/kg = 6.20 m HCOOH
(77.8 g H2O) / (18.01532 g H2O/mol) = 4.3185 mol H2O
(0.48234 mol HCOOH) / (0.48234 mol + 4.3185 mol) = 0.100 [the mole fraction of HCOOH]
