Answer: Ca2+
Explanation: calcium is most like to form Ca2+ because it has 2 electrons in it outermost shell. So it can only contribute 2 electrons for bonding.
Answer:
The main reason why some stable ionic compounds have +1 charged ions, even though other higher would have a more favorable lattice energy is because;
1. Energy is required to remove each of the electrons in an atom, and the more more the electrons are removed, the smaller the atom radius becomes, with increasing nuclear attraction between the opposite charges.
Note, it is a bit easy to remove a single electron, when compared to 4, 5 or 6 electrons. hence, the reason why Ionic compounds are more stable with + charged ions than others.
2. The stability of an ionic compound is dependent on his lattice energy. And the ions with large charge will have a greater attraction between the cations and anions, hence have higher lattice energy. However, the distance between the ions and the nucleus of the atom plays a major role in the stability of the ion.
Answer: This contains magnesium, Mg2+, and hydroxide, OH–
, ions. Each magnesium ion is +2 and
each hydroxide ion is -1: two -1 ions are needed for one +2 ion, and the formula for magnesium
hydroxide is Mg(OH)2. The (OH)2 indicates there are two OH–
ions. In a formula unit of
Mg(OH)2, there are one magnesium ion and two hydroxide ions; or one magnesium, two
oxygen, and two hydrogen atoms. The subscript multiplies everything in ( )
hope that helped!!
Using PV = nRT, we can calculate the moles of the sample.
874 mmHg = 116,524 Pa
n = PV/RT
n = 116,524 x 294 x 10⁻⁶ / 8.314 x (140 + 273)
n = 9.98 x 10⁻³ mol
moles = mass / Mr
Mr = 0.271/9.98 x 10⁻³
Mr = 27.2
Mass of empirical formula = 14
Repeat units = 27.2 / 14 ≈ 2
Formula of substance:
C₂H₄
Combustion equation:
C₂H₄ + 3O₂ → 2CO₂ + 2H₂O
1 mole produces 2 moles of CO₂, so 3 moles will produce 6 moles CO₂
