Answer:
The evidence showing that there is a chemical reaction taking place is the instantaneous temperature drop once the cold pack is shaken.
Explanation:
When an athlete applies a cold pack to the injury, they shake it before, mixing the water and <em>ammonium-nitrate fertilizer</em> inside the cold pack. This mixing is an endothermic reaction, which means it absorbs heat. In turn, the temperature falls to 35 F for around 10 minutes.
For the basic solution:
11.2 = -log[H+]
[H+] = 6.31 x 10⁻¹²
For the acidic solution:
2.4 = -log[H+]
[H+] = 3.98 x 10⁻³
The difference:
3.98 x 10⁻³ - 6.31 x 10⁻¹²
≈ 4.0 x 10⁻³
The answer is B
The number of Ml of a 0.40 %w/v solution of ,nalorphine that must be injected to obtain a dose of 1.5 mg is calculated as below
since M/v% is mass of solute in grams per 100 ml
convert Mg to g
1 g = 1000 mg what about 1.5 mg =? grams
= 1.5 /1000 = 0.0015 grams
volume is therefore = 100 ( mass/ M/v%)
= 100 x( 0.0015/ 0.4) = 0.375 ML
Given problem:
S₂O₈²⁻
Find the oxidation number of S;
Oxidation number presents the extent of oxidation of each atom of elements a molecular formular or formula unit or an ionic radical.
For radicals:
"the algebraic sum of all the oxidation numbers of all atoms in an ion containing more than one kind of atom is equal to the charge on the ion "
S₂O₈²⁻; oxidation number of O is usually -2
2(S) + 8(-2) = -2
2S - 16 = -2
2S = -2 + 16
2S = 14
S = +7
The oxidation state of S in the radical is +7
