Answer:
B. Periods
Explanation:
The horizontal rows in the periodic table are periods.
on the picture below, u can see an example
Answer:
The reaction is exothermic as the solution becomes warm.
Explanation:
Hello there!
In this case according to the described reaction between sodium metal and water, we can write up the chemical equation whereas the products turn out to be sodium hydroxide and hydrogen gas:
Moreover, these reactions are known to be highly exothermic, for that reason the solution becomes warm as the reaction releases heat as it goes to completion.
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The balanced equation for the above reaction is as follows;
2Ca + O₂ ---> 2CaO
stoichiometry of Ca to O₂ is 2:1
we first need to find the limiting reactant
number of Ca moles - 6.84 mol
number of O₂ moles - 4.00 mol
if Ca is the limiting reactant
if 2 mol of Ca reacts with 1 mol of O₂
then 6.84 mol of Ca reacts with - 6.84 / 2 = 3.42 mol of O₂
this means that Ca is the limiting reactant and O₂ is in excess
therefore amount of CaO produced depends on amount of limiting reactant present
stoichiometry of Ca to CaO is 2:2
number of moles of Ca reacted = number of CaO moles formed
number of moles of CaO formed - 6.84 mol
answer is 6.84 mol
<h3>
Answer:</h3>
= +0.43 V
<h3>
Explanation:</h3>
The two standard reduction potentials are;
Fe³⁺(aq) + e⁻ → Fe²⁺(aq) E₀ = +0.77 V
Cu²⁺(aq) + 2e⁻ → Cu(s) E₀ = +0.34 V
The overall reaction is;
Fe³⁺(aq) + Cu(s) → Fe²⁺(aq) + Cu²⁺(aq)
To calculate the standard cell potential of the overall reaction, we use the equation;
Ecell = E redu, cathode - E red, anode
From the reaction; Copper lost electrons to form copper ions (Cu²⁺) (Oxidation) while Fe³⁺ gained electrons to form Fe²⁺ (reduction)
Therefore;
E cell = + 0.77 v - (+0.34 v)
= + 0.43 V
Hence, the standard cell potential of the overall reaction is +0.43 V
1.) A compound is a substance that originates from two or more separate elements. It shares some similarities with a mixture.
2.) A compound has quite different properties from which it was formed. It also cannot be separated easily. Compounds are formed by chemical reactions.
3.) A pure substance has a constant composition and has consistent properties. It can be a compound or an element, but its composition is constant.
Hope this helps. :)