Answer:
9.24% the percent of Mg in the mixture.
Explanation:
Mass of silver bromide = 1.1739 g
Moles of silver bromide = 
1 mole of AgBr has 1 mole of bromine atom.Then 0.006244 moles AgBr has 0.006244 mole bromine atom.
Moles of bromine atoms = 0.006244 moles
Magnesium bromide has 2 moles of bromine atom.Then 0.006244 moles of bromine atoms will be in :
Magnesium bromide has 1 mole magnesium atom, then 0.003122 moles of magnesium bromide will have :
magnesium atom
Mass of 0.003122 moles of magnesium :
0.003122 mol × 24 g/mol = 0.07493 g
Mass of the sample = 0.8107 g
Percentage of magnesium in the sample ;
9.24% the percent of Mg in the mixture.
Answer:
Argon gas
Explanation:
Between the options given, argon gas is the least reactive. Argon is known as a <em>noble gas</em>, this means that it is located in the group 18 in the periodic table. These gases are known for their low reactivity, under most circumstances.
The <u>electronic configuration</u> of argon helps us see why that is the case: With an atomic number of 18, it has an electronic configuration of 1s² 2s² 2p⁶ 3s² 3p⁶. This means the most external orbital is filled with electrons, meaning that there are not unpaired electrons able to react with other substances.
Answer:
This will be the balanced half reaction:
NO₂(g) + H₂O (l) → NO₃⁻(aq) + 1 e⁻ + 2H⁺ (aq)
Explanation:
In acidic medium, the redox balance has to be done as this way.
As it is an oxidation, we know that oxidation state has increased.
NO₂(g) → NO₃⁻(aq) + 1 e⁻
Nitrogen in NO₂ acts with +4; in the nitrate, N acts with +5
The nitrogen has released 1 electron.
As we are in acidic medium, we must complete with water, in the same side, as we have less oxygens and in the opposite side, with protons to balance the H. This will be the balanced half reaction:
NO₂(g) + H₂O (l) → NO₃⁻(aq) + 1 e⁻ + 2H⁺ (aq)
