The original sample of potassium phosphate octahydrate had a mass of 19.6 grams. When it was heated, it released 7.93 grams of water.
Further Explanation:
For every mole of the compound potassium phosphate octahydrate, there are 8 moles of water of hydration which can be removed from the crystal by heating without altering the chemical composition of the substance.
To determine how much original sample was used, the amount of water released upon heating may be used as well as the mole ratio of the water of hydration with the compound itself following the steps below:
- Convert mass of water released to moles.
- Use the mole ratio of water of hydration to the compound (8 mol water for every mol of potassium phosphate octahydrate) to get the moles of original sample.
- Convert the moles of original sample to grams.
STEP 1: Convert 7.93 g water to moles.

STEP 2: Calculate the moles of original sample using the mole ratio: 1 mol K3PO4 8H2O : 8 mol H2O.

STEP 3: Convert the moles of original sample to mass.

Following the significant figures of the given, the final answer should be:

Learn More:
- Learn more about water of hydration brainly.com/question/6053815
- Learn more about mole conversion brainly.com/question/12979299
- Learn more about percent hydrate brainly.com/question/12398621
Keywords: water of hydration, hydrate
Answer:
This question is asking to state the hypothesis for the given scientific question. A possible hypothesis will be:
IF an organized binder is used, THEN students will turn in an increased amount of homework/more homework.
Explanation:
A hypothesis in an experiment is a testable explanation to a problem. It is a predictive statement given in order to provide a possible solution to an observed problem or scientific question. A hypothesis must be subject to testing via experimentation in order to determine whether to accept or reject it. It must not be true, instead it is just a possible answer to a problem. Hypothesis is usually written in the OF, THEN format.
In this question, a scientific question states: How does the use of an organized binder affect the amount of homework a student turns in? Based on the explanation above, a hypothesis to this question will be:
IF an organized binder is used, THEN students will turn in more homework.
Answer: The vapor pressure of water at 298 K is 3.565kPa.
Explanation:
The vapor pressure is determined by Clausius Clapeyron equation:

where,
= initial pressure at 298 K = ?
= final pressure at 373 K = 101.3 kPa
= enthalpy of vaporisation = 41.1 kJ/mol = 41100 J/mol
R = gas constant = 8.314 J/mole.K
= initial temperature = 298 K
= final temperature = 373 K
Now put all the given values in this formula, we get
![\log (\frac{101.3}{P_1})=\frac{41100}{2.303\times 8.314J/mole.K}[\frac{1}{298K}-\frac{1}{373K}]](https://tex.z-dn.net/?f=%5Clog%20%28%5Cfrac%7B101.3%7D%7BP_1%7D%29%3D%5Cfrac%7B41100%7D%7B2.303%5Ctimes%208.314J%2Fmole.K%7D%5B%5Cfrac%7B1%7D%7B298K%7D-%5Cfrac%7B1%7D%7B373K%7D%5D)


Therefore, the vapor pressure of water at 298 K is 3.565kPa.
Answer:
a. 100.0 mL of 0.10 M NH₃ with 100.0 mL of 0.15 M NH₄Cl.
c. 50.0 mL of 0.15 M HF with 20.0 mL of 0.15 M NaOH.
Explanation:
A buffer system is formed in 1 of 2 ways:
- A weak acid and its conjugate base.
- A weak base and its conjugate acid.
Determine whether mixing each pair of the following results in a buffer.
a. 100.0 mL of 0.10 M NH₃ with 100.0 mL of 0.15 M NH₄Cl.
YES. NH₃ is a weak base and NH₄⁺ (from NH₄Cl ) is its conjugate base.
b. 50.0 mL of 0.10 M HCl with 35.0 mL of 0.150 M NaOH.
NO. HCl is a strong acid and NaOH is a strong base.
c. 50.0 mL of 0.15 M HF with 20.0 mL of 0.15 M NaOH.
YES. HF is a weak acid and it reacts with NaOH to form NaF, which contains F⁻ (its conjugate base).
d. 175.0 mL of 0.10 M NH₃ with 150.0 mL of 0.12 M NaOH.
NO. Both are bases.
Hey buddy I am here to help!
1. C
2. A
3. A & B
4. C
5. C
6. A
7. A
8. A & C
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