Answer:
Model A
Explanation:
Model A represents an atom that is more reactive than the others represented.
Valence electrons actually determine the reactivity of elements. They also determine the properties of elements.
Elements with one valence electron are highly reactive because they need low energy to remove them. They can either gain more electrons to become stable or they share/give out their electrons.
Therefore, Model A is the correct answer because it has one valence electron and its valence electron is farther from the nucleus thereby this makes it more reactive.
SO₄²⁻ +NH₃ → SO₃²⁻ + H₂O +N₂
The balanced of the above redox reaction is as below
3SO₄²⁻ + 2NH₃ → 3SO₃²⁻ + 3 H₂O + N₂
Explanation
According to the law of mass conservation the number of atoms in the reactant side must be equal to number of atoms in product side.
Inserting coefficient 3 in front of SO₄² , 2 in front of NH₃, 3 in front of SO₃²⁻ and 3 in front of H₂O balance the equation above. This is because the number of atoms are equal in both side.
for example there are 2 atoms of N in both side of the reaction.
First we determine the
moles CaCl2 present:
525g / (110.9g/mole) =
4.73 moles CaCl2 present
Based on stoichiometry,
there are 2 moles of Cl for every mole of CaCl2:<span>
(2moles Cl / 1mole CaCl2) x 4.73 moles CaCl2 = 9.47 moles Cl </span>
Get the mass:<span>
<span>9.47moles Cl x 35.45g/mole = 335.64 g Cl</span></span>
Answer:
Explanation:
<u>1. Word equation:</u>
- <em>mercury(II) oxide → mercury + oxygen </em>
<u>2. Balanced molecular equation:</u>
<u>3. Mole ratio</u>
Write the ratio of the coefficients of the substances that are object of the problem:
<u>4. Calculate the number of moles of O₂(g)</u>
Use the equation for ideal gases:
<u>5. Calculate the number of moles of HgO</u>
<u>6. Convert to mass</u>
- mass = # moles × molar mass
- molar mass of HgO: 216.591g/mol
- mass = 0.315mol × 216.591g/mol = 68.3g
Answer:
B. The pressure has increased
Explanation:
