Option B: 4.3
There are following rules for rounding off numbers:
1. If the rounding digit has digit less than 5 (1,2,3 and 4) to its right, all the digits on right side of the rounding digit will drop out.
2. If the rounding digit has digit equal and greater than 5 (5,6,7,8 and 9) to its right, one is added to the rounding digit.
Jeff has to weigh 4.312 g sample of NaCl. To round off the underline number 4.<u>3</u>12, check for the digit right to it. It has 1, which is less than 5 thus according to the Rule 1, all the digits on right side of the rounding digit will drop out and the number gets rounded off to 4.3.
Therefore, 4.3 is most accurate measurement by Jeff.
When the pH falls below 7.35, <span>a state of acidosis exists.
</span>The normal pH in the mammals arterial blood is between 7.35 and 7.50, so a<span>cidosis occurs when arterial </span>pH falls below 7.35. Acidosis is a process causing increased acidity (<span>increased </span>hydrogen ion or proton H⁺ concentration) in the blood and other body tissues.
Alkalosis<span> occurs at a pH over 7.45.</span>
<span>Answer:
The rate equation for a nucleophilic substitution reaction of a tertiary reagent.</span>
Meteor, dwarf planet, asteroid, planet
2Na + 2H2O ——> 2 NaOH + H2