Mass <span>is a measure of the quantity of matter in an object</span>
Answer:
78.04g of 0.448 moles must be added
Explanation:
Using H-H equation we can find the pH of the buffer:
pH = pKa + log [A⁻] / [HA]
<em>Where pH is the pH of the buffer = 7.2</em>
<em>pKa = 7.1</em>
<em>[A⁻] = [K₂HPO₄]</em>
<em>[HA] = [KH₂PO₄]</em>
<em />
Replacing:
7.2 = 7.1 + log [K₂HPO₄] / [KH₂PO₄]
0.1 = log [K₂HPO₄] / [KH₂PO₄]
1.2589 = [K₂HPO₄] / [KH₂PO₄] <em>(1)</em>
<em />
And as the concentration of the buffer is:
1M = [K₂HPO₄] + [KH₂PO₄] <em>(2)</em>
<em></em>
Replacing (2) in (1):
1.2589 = 1M - [KH₂PO₄] / [KH₂PO₄]
1.2589 [KH₂PO₄] = 1M - [KH₂PO₄]
2.2589 [KH₂PO₄] = 1M
[KH₂PO₄] = 0.44M
And [K₂HPO₄] = 0.56M
In 800mL = 0.8L:
0.8L * (0.56mol / L) = 0.448 moles K₂HPO₄. The mass is -Molar mass K₂HPO₄: 174.2g/mol-:
0.448 moles * (174.2g / mol) =
<h3>78.04g of 0.448 moles must be added</h3>
Mass of the compound = 205 g
Molar Mass of compound = ((24) + (2 * 32) + (3 * 16))
= 136 g / mol
∴ # mols in 205g =
= 1.507 mol
<em></em>hydrogen #1 carbon #6 nitrogen #7 oxygen #8 Phosphorus #15 Sulfur #16 Selenium #34
I don't know what model you're referring to so I can't answer the question. However, upon researching, I found a similar problem. I posted it as an attached picture. Looking at the model, the amount of grams a herbivore eat each day corresponds to the arrow pointing inwards. Since the label says 4.0 g,
<em>the answer is 4 g per day</em>.