<span>C. Their direction of motion is south and north. </span>
Answer:
4 1/2
Explanation:
Use a ratio to find your answer
4 6
----- = -------
3 x
Cross multiply to solve for x.
4x = 18
x = 18/4
x = 4 2/4 which is the same as 4 1/2
Explanations:
<u>Question</u> <u>1:</u> Lithium in 20.00+ g is C. or D., but 25.00+ g is D. which means this is the correct option.
I am unsure of <u>Question</u> <u>2</u>. I don't think it is mole though.
<u>Question</u> <u>3:</u> Boron in 25.00-30.00 g is B. or D., but 25.00 g would be C.
<u>Question</u> <u>4:</u> 2.393 x 1024 atoms of Oxygen is 63.58 mole O. I don't know for sure, but I think this is correct.
<u><em>I am NOT professional. There is a chance I am incorrect. Please reply to me if I've made a mistake.</em></u>
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
