Answer:
NO2- is the reducing agent.
Cr2O7_2- is the oxidizing agent.
H+ is neither
Explanation:
Reduction is the gain in electron. A chemical specie that undergoes reduction is called the oxidizing agent.
Oxidation is simply the loss in electrons. A chemical specie that undergoes oxidation is called the reducing agent.
Let us look at the species.
The first specie is the NO2-. In this specie, the oxidation number of nitrogen changed from +3 to +5 in NO3-. Thus we can see that there is more loss of electron to have caused an increase in the oxidation number positively. This shows an oxidation. Hence, NO2- is the reducing agent.
Let us look at the chromium. We can see that the oxidation number of chromium changed from +7 to +3.
Now we can see that it is a decrease and hence, it is a gain of electron and thus it is reduction. This means the first chromium specie is the oxidizing agent.
The hydrogen ion is simply placed there to balance the ions and hence it is neither the oxidizing nor the reducing agent.
<span>Answer: option B. 3.07 g
Explanation:
1) given reaction:
S(s) + O₂ (g) → SO(g)
2) Balanced chemical equation:
</span><span>2S(s) + O₂ (g) → 2SO(g)
3) Theoretical mole ratios:
2 mol S : 1 mol O₂ : 2 mol SO
3) number of moles of 4.5 liter SO₂ at</span><span> 300°C and 101 kPa
use the ideal gas equation:
pV = nRT
with V = 4.5 liter
p = 101 kPa
T = 300 + 273.15 K = 573.15 K
R = 8.314 liter×kPa / (mol×K)
=> n = pV / (RT) =
n = [101 kPa × 4.5 liter] / [8.314 (liter×kPa) / (mol×K) × 573.15 K ]
n = 0.0954 mol SO
4) proportion with the theoretical ratio S / SO
2 mol S x
-------------- = ----------------------
2 mol SO 0.0954 mol SO
=> x = 0.0954 mol S.
5) Convert mol of S to grams by using atomic mass of S = 32.065 g/mol
mass = number of moles × atomic mass
mass = 0.0954 mol × 32.065 g/mol = 3.059 g of S
6) Therefore the answer is the option B. 3.07 g
</span>
If 40.0 grams of magnesium is reacted with an excess of nitric acid. 3.3 g of hydrogen gas will be produced.
<h3>What is Stoichiometry ?</h3>
Stoichiometry helps us use the balanced chemical equation to measure quantitative relationships and it is to calculate the amounts of products and reactants that are given in a reaction.
<h3>What is Balanced Chemical Equation ?</h3>
The balanced chemical equation is the equation in which the number of atoms on the reactant side is equal to the number of atoms on the product side in an equation.
Now we have to write the balanced equation
Mg + 2HNO₃ → Mg(NO₃)₂ + H₂
According to Stoichiometry

= 3.3 g H₂
Thus from the above conclusion we can say that If 40.0 grams of magnesium is reacted with an excess of nitric acid. 3.3 g of hydrogen gas will be produced.
Learn more about the Stoichiometry here: brainly.com/question/16060223
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Answer:
Element
Explanation:
Each different kind of atom represents an atom. Elements like atoms are considered to be distinct substances that cannot be split into simpler substances. Such substances are known to be made up of just one kind of atom.
Like an atom, elements are made up of protons, neutrons and electrons. Both the protons and neutrons are found in the nucleus of the atom.