Answer:
B and D could be true
Explanation:
A volume of sodium hydroxide less than expected could occurs for two reasons:
The real concentration of sodium hydroxide was higher than expected or the amount of vinegar added was less than expected:
A. The sodium hydroxide solution had been allowed to stand exposed to the air for a long time prior to the titration. FALSE. A long expose to the air decreases concentration of the NaOH.
B. The volumetric flask used to prepare the diluted vinegar solution was rinsed with water prior to use. TRUE. You add a less amount of vinegar doing you require less amount of NaOH than expected.
C. The burette used to deliver the sodium hydroxide solution was rinsed with water prior to use. FALSE. Thus, you add a less amount of NaOH than expected. To explain the matter, you add more NaOH than expected.
D. The pipette used to deliver the vinegar solution was rinsed with water prior to use. TRUE. Again, you are adding a less amount of Vinegar than expected doing the necessary NaOH during titration less than expected
Answer:
19.264×
atoms are present in 3.2 moles of carbon.
Explanation:
It is known that one mole of each element is composed of Avagadro's number of atoms. This is same for all the elements in the periodic table.
So, as 1 mole of any element = Avagadro's number of atoms = 6.02×
atoms
It is as simple as understanding a dozen of anything is equal to 12 pieces of that object.
As here the moles of carbon is given as 3.20 moles, the number of atoms in this mole can be determined as below.
1 mole of carbon = 6.02 ×
atoms
Then, 3.20 moles of carbon = 3.20 × 6.02 ×
atoms
Thus, 19.264×
atoms are present in 3.2 moles of carbon.
A) Energy is released during the formation of the bond.
Explanation:
During the formation of a chemical bonds between two hydrogen atoms, energy is always released during the formation of this bond type.
Bond formation process is usually exothermic and energy is released during the formation of the bond.
- Bond breaking process is an endothermic process in which energy is absorbed from the surrounding.
- Whenever a bond is broken, the bond energy value is positive but when a bond is formed, the bond energy value is given a negative sign.
For a bond formation process in which hydrogen atoms are bonded covalently, energy is usually released.
Learn more:
Enthalpy changes brainly.com/question/10567109
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B, turns red litmus paper to blue
Answer:
The new pressure will be 0.225 kPa.
Explanation:
Applying combined gas law:

where,
are initial pressure and volume at initial temperature
.
are final pressure and volume at initial temperature
.
We are given:



Putting values in above equation, we get:


Hence, the new pressure will be 0.225 kPa.