I think the answer is the last answer at the bottom
1 mole ----------- 6.02 x 10²³ atoms
? mole ---------- 24.08 x 10²³ atoms
moles B = ( 24.08 x 10²³) x 1 / 6.02 x 10²³
moles B = 24.08 x 10²³ / 6.02 x 10²³
= 4 moles
Answer B
hope this helps!
False. ......................................
Explanation:
Since HF is a weak acid, the use of an ICE table is required to find the pH. The question gives us the concentration of the HF.
HF+H2O⇌H3O++F−HF+H2O⇌H3O++F−
Initial0.3 M-0 M0 MChange- X-+ X+XEquilibrium0.3 - X-X MX M
Writing the information from the ICE Table in Equation form yields
6.6×10−4=x20.3−x6.6×10−4=x20.3−x
Manipulating the equation to get everything on one side yields
0=x2+6.6×10−4x−1.98×10−40=x2+6.6×10−4x−1.98×10−4
Now this information is plugged into the quadratic formula to give
x=−6.6×10−4±(6.6×10−4)2−4(1)(−1.98×10−4)−−−−−−−−−−−−−−−−−−−−−−−−−−−−√2x=−6.6×10−4±(6.6×10−4)2−4(1)(−1.98×10−4)2
The quadratic formula yields that x=0.013745 and x=-0.014405
However we can rule out x=-0.014405 because there cannot be negative concentrations. Therefore to get the pH we plug the concentration of H3O+ into the equation pH=-log(0.013745) and get pH=1.86
Hey, the two answers that would best fit in the blank would be B.) reproduce by mitosis & D.) Have 46 chromosome pairs.
Sentence form: Skin cells reproduce by mitosis and have 46 chromosome pairs.
