The correct answer is 12.044 × 10²³ molecules.
The molecular mass of H₂S is 34 gram per mole.
Number of moles is determined by using the formula,
Number of moles = mass/molecular mass
Given mass is 68 grams, so no of moles will be,
68/34 = 2 moles
1 mole comprises 6.022 × 10²³ molecules, therefore, 2 moles will comprise = 6.022 × 10²³ × 2
= 12.044 × 10²³ molecules.
Answer:
When two atoms are very far apart, the potential energy approaches zero.
Answer:
when mass is 1×10⁴ Kg then density is 5 g/cm³.
when mass is 104 Kg then density is 5.2 × 10⁻² g/ cm³.
Explanation:
Density:
Density is equal to the mass of substance divided by its volume.
Units:
SI unit of density is Kg/m3.
Other units are given below,
g/cm3, g/mL , kg/L
Formula:
D=m/v
D= density
m=mass
V=volume
Symbol:
The symbol used for density is called rho. It is represented by ρ. However letter D can also be used to represent the density.
Given data:
mass = 1×10⁴ Kg
volume= w ×l× h = 1×2× 1 = 2 m³
density = ?
first of all we will convert the given volume meter cube to cm³:
we know that
2×1000000 = 2 × 10⁶ cm³
Now we will convert the mass into gram.
1 Kg = 1000 g
1×10⁴ × 1000 = 1 ×10⁷ g
Now we will put the values in the formula,
d = m/v
d = 1 ×10⁷ g / 2×10⁶ cm³
d = 0.5 × 10¹ g/cm³
or
d = 5 g/cm³
If mas is 104 Kg:
104 × 1000 = 104000 g
d= m/v
d = 104000 g / 2×10⁶ cm³
d= 52000 ×10⁻⁶ g/ cm³
d= 5.2 × 10⁻² g/ cm³
Answer:
46.40 g.
Explanation:
- It is a stichiometric problem.
- The balanced equation of the reaction: 4K + O₂ → 2K₂O.
- It is clear that 4.0 moles of K reacts with 1.0 mole of oxygen produces 2.0 moles of K₂O.
- We should convert the mass of K (38.5 g) into moles using the relation:
<em>n = mass / molar mass,</em>
n = (38.5 g) / (39.098 g/mol) = 0.985 mole.
<em>Using cross multiplication:</em>
4.0 moles of K produces → 2.0 moles of K₂O, from the stichiometry.
0.985 mole of K produces → ??? moles of K₂O.
∴ The number of moles of K₂O produced = (0.985 mole) (2.0 mole) / (4.0 mole) = 0.4925 mole ≅ 0.5 mole.
- Now, we can get the mass of K₂O:
∴ mass = n x molar mass = (0.5 mole) (94.2 g/mol) = 46.40 g.
