Answer: x = 63
Step-by-step explanation:
15/3 = 5
3 * 21 = 63
63/15 = 21/5
<span>Answer:
MgF2 ====⇒ Mg+2 + 2F-
Ksp = [Mg+2][F-]^2
Let S = molar solubility of MgF2
[Mg+2] = S ; [F-] = 2s
Since the [F-] is initially 0.40 M, then [F-] = 0.40 + 2S
6.4 x 10^-9 = (S) (0.40 + 2S)^2 ; one can neglect the 2S in the 0.40 + 2S expression since it is very, very small compared to the 0.40 already present.
6.4 x 10^-9 = S(0.40)^2
S = 4.0 x 10^-8
Molar solubility = 4.0 x 10^-8</span>
For 6 plug in each of the answers for x and see if the product =3.2
Answer for 6: A
For 7 you turn the percentage into a decimal and multiply that by the number in which you know and you find the answer.
Answer for 7: D
Answer:

Step-by-step explanation:
V= <em>lwh</em><em> </em>or <em>l</em><em> </em><em>*</em><em>w</em><em>*</em><em>h</em>
<em>Length</em><em>:</em><em> </em><em>15</em>
<em>Width</em><em>:</em><em> </em><em>3</em>
<em>Height</em><em>:</em><em>4</em>
<em>V</em><em>=</em><em>15</em><em>*</em><em>3</em><em>*</em><em>4</em>
V=180
Convert gal to cup
16 cups = 1 gallon
or 16 cuos per gallon
or 16 cups/gallon
1.5 gallons × 16 cups/gallon = 24 cups
(gallons cancel out)