Isotopes are atoms with the same number of protons and electrons but different number of neutrons.
Extra for better understanding:
Thus, the relative atomic mass (Ar) differs amongst the isotope. For example, Chlorine have 2 main isotopes with Ar of 35 and 37. The chemical property of the isotopes is the same but the physical property such as boiling point may change.
Answer:
3.925 mol.
Explanation:
- From the balanced equation:
<em>2 Na₂O₂(s) + 2 H₂O(l) → 4 NaOH(s) + O₂(g)
,</em>
It is clear that 2 moles of Na₂O₂ react with 2 moles of H₂O to produce 4 moles of NaOH and 1 mole of O₂
.
<em>Using cross multiplication:</em>
4 moles of NaOH produced with → 1 mole of O₂
.
15.7 moles of NaOH produced with → ??? mole of O₂
.
<em>∴ The no. of moles of O₂ made =</em> (1 mole)(15.7 mole)/(4 mole) = <em>3.925 mol.</em>
Answer:
7.08
Explanation:
To solve this problem we'll use the <em>Henderson-Hasselbach equation</em>:
- pH = pka + log
![\frac{[A^-]}{[HA]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BA%5E-%5D%7D%7B%5BHA%5D%7D)
Where
is the ratio of [sodium formate]/[formic acid] and pka is equal to -log(Ka), meaning that:
- pka = -log (1.8x10⁻⁴) = 3.74
We<u> input the data</u>:
- 4.59 = 3.74 + log
![\frac{[A^-]}{[HA]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BA%5E-%5D%7D%7B%5BHA%5D%7D)
And<u> solve for </u>
:
- 0.85 = log
![\frac{[A^-]}{[HA]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BA%5E-%5D%7D%7B%5BHA%5D%7D)
=![\frac{[A^-]}{[HA]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BA%5E-%5D%7D%7B%5BHA%5D%7D)
= 7.08
Answer: A: The smoother the ramp surface, the greater the car's speed.
Explanation: I did the USA test prep