A period is a horizontal row of the periodic table. There are seven periods in the periodic table, with each one beginning at the far left. ... A group is a vertical column of the periodic table, based on the organization of the outer shell electrons. There are a total of 18 groups.
Answer: 0.75 moles of Phosphorus and 4.5 moles of Hydrogen are produced respectively from 3 moles of Phosporus.
Explanation:
4PH3 --------> P4 + 6H2
From the stochiometry of the reaction,
4 moles of Phosphine gives 1 mole of Phosphorus
3 moles of Phosphine will give (3×1)/4 moles of Phosphorus.
Therefore, 0.75 moles of Phosphorus is produced.
Similarly, 4 moles of Phosphine gives 6 moles of Hydrogen
3 moles of Phosphine will give (3×6)/4 moles of Hydrogen.
Therefore, 4.5 moles of Hydrogen is produced.
QED!
The first step in balancing any redox reaction is determining whether or not it is even an oxidation-reduction reaction, which requires that species exhibits changing oxidation statesduring the reaction. To maintain charge neutrality in the sample, the redox reaction will entail both a reduction component and an oxidation components and is often separated into independent two hypothetical <span>half-reactions </span>to aid in understanding the reaction. This requires identifying which element is oxidized and which element is reduced. For example, consider this reaction:
<span><span><span>Cu(s)+2A<span>g+</span>(aq)→C<span>u<span>2+</span></span>(aq)+2Ag(s)</span>(1)</span><span>(1)<span>Cu(s)+2A<span>g+</span>(aq)→C<span>u<span>2+</span></span>(aq)+2Ag(s)</span></span></span>
The first step in determining whether the reaction is a redox reaction is to splitting the equation into two hypothetical half-reactions. Let's start with the half-reaction involving the copper atoms:
<span><span><span>Cu(s)→C<span>u<span>2+</span></span>(aq)</span>(2a)</span><span>(2a)<span>Cu(s)→C<span>u<span>2+</span></span>(aq)</span></span></span>
The oxidation state of copper on the left side is 0 because it is an element on its own. The oxidation state of copper on the right hand side of the equation is +2. The copper in this half-reaction is oxidized as the oxidation states increases from 0 in Cu to +2 in Cu2+. Now consider the silver atoms
<span><span><span>2A<span>g+</span>(aq)→2Ag(s)</span>(2b)</span><span>(2b)<span>2A<span>g+</span>(aq)→2Ag(s)</span></span></span>
In this half-reaction, the oxidation state of silver on the left side is a +1. The oxidation state of silver on the right is 0 because it is an element on its own. Because the oxidation state of silver decreases from +1 to 0, this is the reduction half-reaction.
Consequently, this reaction is a redox reaction as both reduction and oxidation half-reactions occur (via the transfer of electrons, that are not explicitly shown in equations 2). Once confirmed, it often necessary to balance the reaction (the reaction in equation 1 is balanced already though), which can be accomplished in two ways because the reaction could take place in neutral, acidic or basic conditions.
Answer. Statement second and third both are correct.
Explanation: When iron(grey) reacts with sulfur(yellow) chemical change takes place in which iron sulfide is formed which black in color.
When we heat copper sulfate-pentahydrate(blue) ,water molecule present in its crystal will get evaporated and it will become an anhydrous copper sulfate which will be white in color.
So, in both the reactions change in color and change in chemical arrangement has taken place.
Answer: A. 0.0375
Explanation:
To calculate the moles :
According to stoichiometry :
As 5 moles of 
give = 2 moles of 
Thus 0.094 moles of give =
of
Thus 0.0375 moles of will be produced when 3.00g of O₂ react completely
