The moles are the estimation of the quantities like the molecules and the atoms. There are 7.984 moles of aluminum present in the 2.154 × 10⁻¹ kg substance. Thus, option b is correct.
<h3>What are moles?</h3>
The moles give the estimation of the smaller entities by the ratio of mass or weight to the molar mass of the substance.
The formula for moles is given as,
Moles = mass ÷ molar mass
Given,
Mass of aluminium = 2.154 × 10⁻¹ kg = 2.154 × 10² gm
Molar mass of Al = 26.9 g/mol
Substituting values above:
Moles = 2.154 × 10² gm ÷ 26.9 g/ mol
= 7.984 mol
Therefore, option. 7.984 moles of aluminum are present.
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75.0 mL in liters:
75.0 / 1000 => 0.075 L
1 mole -------------------- 22.4 L ( at STP)
( moles Hg) ------------- 0.075 L
moles Hg = 0.075 x 1 / 22.4
moles = 0.075 / 22.4
= 0.00334 moles of Hg
Hg => 200.59 u
1 mole Hg ----------------- 200.59 g
<span>0.00334 moles Hg ----- ( mass Hg )
</span>
mass Hg = 200.59 x 0.00334 / 1
mass Hg = 0.6699 / 1
= 0.6699 g of Hg
The volume of a substance is the quantity of the substance present at the definite temperature and pressure.
Explanation:
1ml of water has a volume of one cubic centimeter(1cm3). When a substance is cooled it causes the molecules to slow down and get close together occupies a smaller volume that results in density.
If the hot water is less dense it will float in room temperature and if the cold water is more dense it will sink in room temperature.
Density is the mass per unit volume of a substance. The density of water is given as 1g/cm3. It is mass divided by volume and water is used as the base for establishing the unit of mass which states cubic centimeter(1cm3) of water weighs one gram (1g). If the water is heated it expands or increases in volume. if the volume increases it becomes less dense.
Answer:
CH₃CO₂H + H₂O ⇄ CH₃CO₂⁻ + H₃O⁺
Explanation:
A buffer is defined as the mixture of a weak acid and its conjugate base or vice versa.
For the acetic acid buffer, CH₃CO₂H is the weak acid and its conjugate base is the ion without H⁺, that is CH₃CO₂⁻. The equilibrium equation in water knowing this is:
<h3>CH₃CO₂H + H₂O ⇄ CH₃CO₂⁻ + H₃O⁺</h3>
<em>In the equilibrium, the acid is dissociated in the conjugate base and the hydronium ion.</em>