Which solution has the highest boiling point at standard pressure?(1) 0.10 M KCl(aq)
(2) 0.10 M K2SO4(aq)
(3) 0.10 M K3PO4(aq)
(4) 0.10 M KNO3(aq)

Answers

Answer 1

Answer: The correct answer is 3: 0.10 M K3PO4(aq). The higher the concentration (or molarity), the higher the boiling point. Thus, the solution with the most moles will have the highest boiling point. SO4, PO4, and NO3 are all polyatomic ions, so by definition, they only have one mole. In K3PO4, K3 has 3 moles and PO4 has 1 mole, meaning all together it has 4 moles (more than any of the other options).

0.087 g/mL

Explanation:

The density of a substance can be found by using the formula

$density = (mass)/(volume)$

From the question

mass of liquid = 2.6 g

volume = 30 mL

The density is

$density = (2.6)/(30) \n = 0.08666666...$

We have the final answer as

0.087 g/mL

Hope this helps you

In which sample of water do the molecules have the highest average kinetic energy?(1) 20. mL at 100.°C (3) 60. mL at 60.°C
(2) 40. mL at 80.°C (4) 80. mL at 40.°C

Answers

The answer is (1). The question is asking the average kinetic energy. So it does not related with volume. When temperature increases, the kinetic energy will also increase. So the answer should be the highest temperature.

Why are some elements more reactive than others?

Answers

All other atoms have less stable electron numbers, so they react with each other and share electrons to be more stable. The most reactive elements tend to be short one or two electron or have one or two extra electrons.

because of extra electrons

Answer the following questions: On a 10-fold dilution of a weak acid, the pH will ______________ . On a 10-fold dilution of a weak base, the pH will ______________. If one adds a very small amount of strong base to a buffered solution, the pH will _______________. Can you make a buffer using a strong acid

Answers

Answer:

i) increase

ii) decrease

iii) remain the same

iv) No, because it dissociates completely.

Explanation:

On a 10-fold dilution of a weak acid, the pH will increase because the concentration of hydrogen ions will decrease thereby increasing the pH to close to that of water.

On a 10-fold dilution of a weak base, the pH will decrease due to the removal of hydroxide ions from the solution. This results in the solution having a H closer to that of water.

If one adds a very small amount of strong base to a buffered solution, the pH will remain constant because a buffer solution acts to withstand any change to its pH on the addition of small quantities of either an acid or a base.

A buffer solution cannot be made with a strong acid because thy undergo complete dissociation. Therefore, any small addition of base or acid will result in very large changes in the pH of the solution. A buffer solution is made with a weak acid and its conjugate base or a weak base and its conjugate acid.

juan is planning an investigation about natural reserves. which of these is most likely to be a reliable source of scientific information on the internet

Answers

It depends on the credibility and reliability of the said source. Thus, a primary source is a type of obtaining or sourcing information after the phenomenon occurred at that particular time and when photographs are the first-hand materials that were able to capture that specific moment which then can convey the information. Primary resources also include –newspapers, journal articles, magazines and etc. These information are very vital for its credibility and reliability.

Answer:it’s .gov

Explanation:thanks me later took the test

The purpose of an indicator is to A. test and determine the pH values of unknown solutions. B. help acids and bases dissociate when placed in water. C. make a solution more neutral. D. conduct electricity.

Answers

Answer is: A. test and determine the pH values of unknown solutions.

Acid-base indicators are usually weak acids or bases and they are chemical detectors for hydrogen or hydronium cations (pH or pOH values).

Example for acid-base indicator is phenolphthalein (molecular formula C₂₀H₁₄O₄). Phenolphthalein is colorless in acidic solutions and pink in basic solutions.

Another example is methyl orange. It is red colour in acidic solutions and yellow colour in basic solutions.

Answer: The correct answer is option A.

Explanation:

An indicator is a substance which changes color to show any chemical change happening in the reaction. It gives the visible sign of any change.

Hence, main role of indicators from the given options is to determine the pH values of unknown solutions.

pH is the scale which shows the acidity and basicity of the solutions. It is the negative logarithmic value of hydrogen ion concentration of the solution. More the hydrogen ion concentration, less will be the pH and more acidic will be the solution.

$pH=-\log[H^+]$