Answer:
Option (2) 2
Explanation:
NO3- + 4H+ + Pb → Pb2+ + NO2 + 2H2O
The equation above can be balance as follow:
There are 3 atoms of the left side and a total of 4 atoms on the right side. It can be balance by putting 2 in front NO3- and 2 in front of NO2 as shown below:
2NO3- + 4H+ + Pb → Pb2+ + 2NO2 + 2H2O
Now the equation is balanced.
The coefficient of NO2 is 2
Option A is correct. When a person says "<em>I think</em><em> that between an elephant and a monkey that jumped off the cliff, both of them will hit the ground at the same time."</em> the person is stating his Hypothesis
A hypothesis is an explanation proposed or given based on a piece of evidence that is limited.
It is useful at the beginning of an investigation because it serves as the building block for an impending fact or law.
From the statement, we can see that the person is not too sure of the information provided since he "thinks". <em>He said, </em><em>"I think</em><em> that between an elephant and a monkey that jumped off the cliff, both of them will hit the ground at the same time." </em>
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Hence we can conclude that the person is stating a hypothesis.
Law and theory are incorrect because they are already proven facts.
Learn more here: brainly.com/question/6907236
Answer:
a. The reaction is endothermic.
Explanation:
The heat involved in a chemical reaction is given by the enthalpy change (ΔH), which is equal to the balance between the chemical bonds that are broken (release energy) and the chemical bonds that are formed (need energy):
ΔH ≅ bonds broken - bonds formed
If broken bonds > bonds formed ⇒ ΔH > 0 ⇒ endothermic reaction
Therefore, the reaction is endothermic (it requires energy).
DANNNNNNNNNNNNGGGGGG hella hot, the hottest I seen in this world !!
The balanced chemical equation for the production of chromium metal from the reaction of chromium(ll) nitrate reacts with a strip of zinc is:
3 Zn + 2 Cr(NO₃)₃ → 2 Cr + 3 Zn(NO₃)₂
This is a redox reaction, which <u>is a chemical reaction in which one or more electrons are transferred between the reagents</u>, causing a change in their oxidation states. In the proposed reaction, Cr oxidation state goes from +3 to 0, becoming metallic chromium, while Zn goes from being Zn⁰ to Zn²⁺.
<u>The mass of chromium metal produced in the above reaction will be,</u>
425.0 mL x x x x = 5.52 g
So, the mass of chromium metal produced when 425.0mL of 0.25M chromium(ll) nitrate reacts with a strip of zinc that remains in excess is 5.52 g of Cr.