Answer:
The answer is C
Explanation:
Precision generally means been accurate (and can be loosely interpreted to mean been exact). Length is averagely measured in meters. However, in order to get the actual length of a substance using a tape, millimeters give the most accurate length (of all the options) as it provides the length to the smallest details (of all the options provided). The illustration below shows the relationship between millimeters and the rest of the options.
while 1 kilometer = 1000 meters
1 meter = 100 centimeters
1 centimeter = 10 millimeters
From the relationship above, millimeters is clearly the most precise of all the options provided.
Answer:
Initial concentration of acetic acid (CH3COOH_initial): 0.25 M
pKa for acetic acid: 4.76
Assume x is the concentration of H+ ions formed through dissociation.
CH3COOH ⇌ x (due to dissociation)
Apply the x-is-small approximation: We assume x is much smaller than the initial concentration of acetic acid (0.25 M). Therefore, we can neglect x in comparison to 0.25 M.
Calculate pH using the pKa equation:
Rounded to two decimal places, the pH of the acetic acid solution is approximately 2.68.
Explanation:
18°
23°
45°
60°
b. 16 g
c. 32 g
d. 1.204 × 1024
The correct answer is B.
1 mol O2 x 15.999 O2/ 1 mol O2 = 15.999 O2
16 O2 when rounded.
Answer:
54.2 g of Ca(OH)₂
Explanation:
Let's determine the moles of solute, we should need
Molarity . volume (L) = moles
Let's convert 600 mL to L
600 mL/ 1000 = 0.6L
1.22 mol/L . 0.6L = 0.732 moles
Finally we must convert the moles to mass ( moles . molar mass)
0.732 mol . 74.08 g/mol = 54.2 g
Answer: 54.2 g Ca(OH)2
Explanation: Molarity is moles of solute / L solution
First convert mL to L
600 mL x 1L / 1000 mL = 0.6 L
Find moles of Ca(OH)2
n= M x L
= 1.22 M x 0.6 L
= 0.732 moles Ca(OH)2
Convert moles to mass using its molar mass of Ca( OH)2 = 74 g
0.732 moles Ca(OH)2 X 74 g Ca(OH)2 / 1 mole Ca(OH)2
= 54.2 g Ca(OH)2