Answer:
10.418*10²³
Explanation:
1) 6.022*10²³ moleculas in 1 mole PCl₅ (Avogadro's number);
2) in 1.73 moles: 6.022*10²³*1.73=10.418*10²³
Answer:
Magnitude = 1.51 ×10^6m/s
Direction is to the north
Explanation:
Question:
If an electron in an electron beam experiences a downward force of 2.0 × 10^-14N while traveling in a magnetic field of 8.3 × 10^-2T to the west, what is the direction and magnitude of the velocity?
Solution:
F= 2.0 × 10^-14N
Magnetic force = B = 8.3 × 10^-2T
Let the charge, q= 1.6×10^-19
F = Bqvsinθ
v = F/(Bqsinθ)
v = 2×10^-14/(8.3 × 10^-2 × 1.6×10^-19 ×sin90)
v = 2×10^-14/(13.28×10^-21 × 1)
v = 2/13.28 × 10^-14/10^-21
v = 0.1506 × 10^(-14+21)
v = 0.1506 × 10^7 = 0.151 × 10^7
v = 1.51 ×10^6m/s
Force is going down
magnetic field points west
Using the right and rule:
Point your fingers towards the west, and your thumb will point north. Since this is an electron, use the back of your hand( turn your hand backwards). The thumb points north.
Velocity direction is north
Answer is: the compound is B₂O₃.
ω(O) = 68.94% ÷ 100%.
ω(O) = 0.6894; percentage of oxygen in the compound.
ω(X) = 31.06% ÷ 100%.
ω(X) = 0.3106; percentage of unknown element in the compound.
If we take 69.7 grams of the compound:
M(compound) = 69.7 g/mol.
n(compound) = 69.7 g ÷ 69.7 g/mol.
n(compound) = 1 mol.
n(O) = (69.7 g · 0.6894) ÷ 16 g/mol.
n(O) = 3 mol.
M(compound) = n(O) · M(O) + n(X) · M(X).
n(X) = 1 mol ⇒ M(X) = 21.7 g/mol; there is no element with this molecular weight.
n(X) = 2 mol ⇒ M(X) = 10.85 g/mol; this element is boron (B).
A MOUNTAIN RANGE is a landform with high elevation and a more or less level surface
Answer: 15 grams of salt are there in 5 L of solution.
Explanation:
Concentration of a solution is defined as the number of grams of solute dissolved per liter of the solution.
Given : Concentration of solution : 3 g/L
1 Liter of solution contains = 3 gram of salt
Thus 5 L of solution contains = 
Thus 15 grams of salt are there in 5 L of solution.
