Answer:
Moles of silver iodide produced = 1.4 mol
Explanation:
Given data:
Mass of calcium iodide = 205 g
Moles of silver iodide produced = ?
Solution:
Chemical equation:
CaI₂ + 2AgNO₃ → 2AgI + Ca(NO₃)₂
Number of moles calcium iodide:
Number of moles = mass/ molar mass
Number of moles = 205 g/ 293.887 g/mol
Number of moles = 0.7 mol
Now we will compare the moles of calcium iodide with silver iodide.
CaI₂ : AgI
1 : 2
0.7 : 2×0.7 = 1.4
Thus 1.4 moles of silver iodide will be formed from 205 g of calcium iodide.
Answer: Metals form cations.
The alkali metals (the IA elements) lose a single electron to form a cation with a 1+ charge.
The alkaline earth metals (IIA elements) lose two electrons to form a 2+ cation.
Aluminum, a member of the IIIA family, loses three electrons to form a 3+ cation.
Therefore, metals in the s and p block of the periodic table have 1, 2 or 3 electrons in their outermost orbit (or valence shell). Now to gain a stable octet metals lose either 1, 2 or 3 electrons from the valence shell thus forming cation with +1, +2 or +3 charge.
Answer:
H₂SO₄ (aq) + 2LiOH (aq) ⇒ Li₂SO₄ (aq) + 2H₂O (l)
Explanation:
This is an acid-base reaction, so we know the products are going to a salt/ionic compound and water.
Answer:
10.78 → 4 significant figures, pH = 10.78 → [H⁺] = 1.66ₓ10⁻¹¹ M
6.78 → 3 significant figures, pH = 6.78 → [H⁺] = 1.66ₓ10⁻⁷ M
0.78 → 2 significant figures, pH = 0.78 → [H⁺] = 0.166 M
pH always can be expressed by at least 4 significant figures. The [H⁺], can be expressed by, at least 3 significant figures
Explanation:
Significant figures are the numbers of a measurement that have certainty plus a doubtful number (it is associated with the uncertainty in the measurement). For example, if we measure a paper with a ruler and the ruler measures up to centimeters we can say that the paper is 7.5 cm long, with which we know that the paper is 7 cm + 0.5 cm which we associate with uncertainty. In this case we talk about two significant figures. If the sheet measured 7.57 cm we would already be talking about a more precise measurement and in this case with 3 significant figures.
10.78 → 4 significant figures
6.78 → 3 significant figures
0.78 → 2 significant figures
To determine [H⁺], we apply 10^-pH
10⁻¹⁰°⁷⁸ = 1.66ₓ10⁻¹¹ M
10⁻⁶°⁷⁸ = 1.66ₓ10⁻⁷ M
10⁻⁰°⁷⁸ = 0.166 M
