Answer:
the answer is B =the weighted average of the masses of the isotopes of the element
Question #1
Potasium hydroxide (known)
volume used is 25 ml
Molarity (concentration) = 0.150 M
Moles of KOH used
0.150 × 25/1000 = 0.00375 moles
Sulfuric acid (H2SO4)
volume used = 15.0 ml
unknown concentration
The equation for the reaction is
2KOH (aq)+ H2SO4(aq) = K2SO4(aq) + 2H2O(l)
Thus, the Mole ratio of KOH to H2SO4 is 2:1
Therefore, moles of H2SO4 used will be;
0.00375 × 1/2 = 0.001875 moles
Acid (sulfuric acid) concentration
0.001875 moles × 1000/15
= 0.125 M
Question #2
Hydrogen bromide (acid)
Volume used = 30 ml
Concentration is 0.250 M
Moles of HBr used;
0.25 × 30/1000
= 0.0075 moles
Sodium Hydroxide (base)
Volume used 20 ml
Concentration (unknown)
The equation for the reaction is
NaOH + HBr = NaBr + H2O
The mole ratio of NaOH : HBr is 1 : 1
Therefore, moles of NaOH used;
= 0.0075 moles
NaOH concentration will be
= 0.0075 moles × 1000/20
= 0.375 M
The answer is carbon, silicone, germanium
B parts eroded by wind or water
In the reaction between a monosaccharide and a ferric ion, The carbonyl carbon is oxidized to a carboxyl group, the cupric ion is reduced.
Chemical reactions often involve color changes, temperature changes, gas evolution, or precipitate formation. Simple examples of everyday reactions are digestion, combustion, and cooking. A physical reaction is a reaction in which a change in matter or physical properties of matter occurs. Physical properties include density, mass, and volume. The definition of a physical reaction is a reaction in which molecules undergo molecular rearrangements but do not change chemically.
As the name suggests, simple reactants form or synthesize more complex products. The basic form of a synthetic reaction is A + B → AB. A simple example of a synthetic reaction is the formation of water from its elements hydrogen and oxygen: 2 H2(g) + O2(g) → 2 H2O(g)9 May 2019
Learn more about the reaction here
brainly.com/question/11231920
#SPJ4
