Answer:
The answer is 1.06g.
Explanation:
Analysis of question:
1. Identify the information in the question given.
- volume of HCl is 2 dm3
- pH of HCl is 2.0
2. What the question want?
- mass of Na2CO3 is ?(unknown)
- 3. Do calculation.
- 1st-Write a balanced chemical equation:
Na2CO3 + 2HCl (arrow) 2NaCl + H20 + CO2
- 2nd-Determine the molarity of HCl with the value of 2.0.
pH= -log[H+]
2.0= -log[H+]
log[H+]= -2.0
[H+]= 10 to the power of negative 2(10-2)
=0.01 mol dm-3
molarity of HCl is 0.01 mol dm-3
- 3rd-Find the number of moles of HCl
n=MV
=0.01 mol dm-3 × 2 dm3
=0.02 mol of HCl
- 4th-Find the second mol of it.
Based on the chemical equation,
2.0 mol of HCl reacts with 1.0 mol of Na2CO3
0.02 mol of HCl reacts with 0.01 mol of Na2CO3
<u>N</u><u>a</u>2CO3>a=<u>1</u><u> </u>mol
<u>2</u><u>H</u>Cl>b=<u>2</u><u> </u>mol
mass= number of mole × molar mass
g=0.01 × [2(23)+ 12+ 3(16)]
g=0.01 × 106
# =1.06 g.
The <span>Kinetic Theory of Matter.
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Answer:
Explanation:
Accuracy is defined is as the ability to perfectly repeat results in an experiment. It is simply reproducing the same set of result with little to no altercation.
Precision is nearness of the result to the true value.
(a) Checking for consistency in the weight of chocolate chip cookies: 17.27 g, 13.05 g, 19.46 g, 16.92 g
The result above is neither accurate nor precise. We can see a lot of inconsistencies in the readings shown and no repeatability whatsoever.
(b) Testing the volume of a batch of 25- mL pipettes: 27.02mL, 26.99 mL, 26.97 mL, 27.01 mL
The results here are accurate but not precise. They are a little bit off the 25mL mark but the experiment was able to reproduce nearly the same result.
(c)Determining the purity of gold: 99.9999%, 99.9998%, 99.9999%
This result is both precise and accurate. Pure Gold should be 100% and our values are very close. The experiment also was able to generate very accurate results.
The density of Jena’s smoothie is 0.667 g/mL.
Mass = 200 g
Volume = 300 mL
Density = mass/volume = 200 g/300 mL = 0.667 g/mL
I believe that the answer is Oxygen. Hope this helps. :)