Which of the following statements is incorrect?

1 answer:

4 0

The correct option is D.
Mole is a measurement used in chemistry which allows us to measure out the same quantity of matter in different substances. Mole allows scientist to measure two substances, for instance, magnesium and sodium, which have equal amount of atoms. Thus, a mole of magnesium contains the same number of atoms as a mole of sodium.

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10. What could the pH of a solution be if a cyanidin indicator turned blue? What is used to determine the endpoint of a titratio

Leviafan [203]

Answer:

The cyanidin indicator turns blue within a pH range of 5 - 7. The pH of the solution could be 5, 6 or 7.

An indicator is used to determine the endpoint of a titration.

Explanation:

Cyanidin indicator changes colour with each change in pH. In acidic solutions (pH < 7) cyanidin indicator will turn red, through to purple and blue, while in basic solutions (pH > 7), cyanidin indicator will change colour from aquamarine through to green and yellow. The cyanidin indicator turns blue within a pH range of 5 - 7.

Titration is a technique used in analytical chemistry to determine the unknown concentration of a solution. A solution of known concentration is added from a burette to the solution of unknown concentration until the reaction between the two solutions is complete. This known as the endpoint of the experiment. The endpoint of a titration is determined using an indicator which is added to reaction mixture. A colour charge is produced by the indicator at the endpoint of the reaction.

Note: An indicator is a dye of weak organic acids or bases which changes colour with changes in the pH of a solution. Some common indicators are methyl orange, methyl red, phenolphthalein, etc. These indicators are used to monitor the changes in the pH of solutions during a reaction.

7 0

3 years ago

Which of the following has no electrons? Use a periodic table. Question 1 options: H He H– He 2+ Save

Elodia [21]

An electron is a negatively charged subatomic particle present in the space outside the nucleus of an atom. The loss of electron from an atom results in the formation of cation whereas gaining of electron by an atom results in the formation of anion. The cation possesses positive charge due to loss of electron and anion possesses negative charge due to gain of electron.

The neutral atom has no charge on it.

For given atomic symbols:

The atomic number of hydrogen is 1 and the given symbol has no charge that means it is in its neutral state. So, the number of electrons in $H$ is 1.

$He$

The atomic number of helium is 2 and the given symbol has no charge that means it is in its neutral state. So, the number of electrons in $He$ is 2.

$H^{-}$

The atomic number of hydrogen is 1 and the given symbol has a negative charge that represents a gain of electron. So, the number of electrons in $H^{-}$ is 2.

$He^{2+}$

The atomic number of helium is 2 and the given symbol has two positive charge that represents loss of two electrons. So, the number of electrons in $He^{2+}$ is 0.

Hence, $He^{2+}$ has no electrons.

6 0

4 years ago

What is the mixture of mercury and one or more metals

Assoli18 [71]

What is <span>Amalgam? hope this helps</span>

5 0

3 years ago

Relative to electrons and electron states, what does the ml quantum number specify

Anastaziya [24]

<span>Magnetic quantum number specify orientation of electrons in magnetic field </span>and number of electron states (orbitals) in subshells..
Magnetic quantum number (ml) specifies the orientation in space of an orbital of a given energy and shape . Magnetic quantum number divides the subshell into individual orbitals which hold the electrons, there are 2l+1 orbitals in each subshell. For example, p orbitals (and their electrons) have three orientations in spase (px, py and pz).

8 0

3 years ago

A balloon filled with helium has a volume of 4.5 × 103 L at 25°C. What volume will the balloon occupy at 50°C if the pressure su

Tom [10]

Answer:

$V_2 = 4.87 * 10^3$