How did Mendeleev set up his Periodic Table of Elements?

PLEASE HELP ME SOLVE THIS.Thank you so much!

Tju [1.3M]

Answer: The coefficients for the given reaction species are 1, 6, 2, 3.

Explanation:

The given reaction equation is as follows.

$Cr_{2}O^{2-}_{7} + Cl^{-} \rightarrow Cr^{3+} + Cl_{2}$

Now, the two half-reactions can be written as follows.

Reduction half-reaction: $Cr_{2}O^{2-}_{7} + 3e^{-} \rightarrow Cr^{3+}$

This will be balanced as follows.

$Cr_{2}O^{2-}_{7} + 14H^{+} + 6e^{-} \rightarrow 2Cr^{3+} + 7H_{2}O$ ... (1)

Oxidation half-reaction: $Cl^{-} \rightarrow Cl_{2} + 1e^{-}$

This will be balanced as follows.

$6Cl^{-} \rightarrow 3Cl_{2} + 6e^{-}$ ... (2)

Adding both equation (1) and (2) we will get the resulting equation as follows.

$Cr_{2}O^{2-}_{7} + 14H^{+} + 6Cl^{-} \rightarrow 2Cr^{3+} + 3Cl_{2} + 7H_{2}O$

Thus, we can conclude that coefficients for the given reaction species are 1, 6, 2, 3.

6 0

3 years ago

Using stoichiometry, determine the mass of powdered drink mix needed to make 1.0 M solution of 100 mL

Rzqust [24]

Answer:

34.23 g.

M = (no. of moles of solute)/(V of the solution (L)).

6 0

3 years ago

A solution is prepared by dissolving 0.23 mol of benzoic acid and 0.27 mol of sodium benzoate in water sufficient to yield 1.00

Monica [59]

Answer:

The pH does not decrease drastically because the NaOH reacts with the D) Benzoic acid present in the buffer solution.

Explanation:

The hydroxide ions will react with acidic part of the solutions, it means the benzoic acid, so it will form the conjugate base, the benzoate ion.

7 0

3 years ago

How reactive is an atom of Sodium(Na) and why?

cricket20 [7]

The correct option is this: SODIUM IS VERY REACTIVE BECAUSE IT DOES NOT HAVE A FULL VALENCE SHELL.
For an atom to attain an octet form, it must have eight electrons in its outermost shell. Elements with eight electrons in their outermost shells are un-reactive. Sodium has only one electron in its outermost shell, this makes it to be very reactive because it is very willing to react with suitable elements in order to become stable.

5 0

3 years ago

Read 2 more answers

Draw the Lewis structure for methane (CH4) and ethane (C2H6) in the box below. Then predict which would have the higher boiling

Alinara [238K]

Answer:

Ethane would have a higher boiling point.

Explanation:

In this case, for the lewis structures, we have to keep in mind that all atoms must have 8 electrons (except hydrogen). Additionally, each carbon would have 4 valence electrons, with this in mind, for methane we have to put the hydrogens around the carbon, and with this structure, we will have 8 electrons for the carbon. In ethane, we will have a bond between the carbons, therefore we have to put three hydrogens around each carbon to obtain 8 electrons for each carbon.

Now, the main difference between methane and ethane is an additional carbon. In ethane, we have an additional carbon, therefore due to this additional carbon, we will have more area of interaction for ethane. If we have more area of interaction we have to give more energy to the molecule to convert from liquid to gas, so, the ethane will have a higher boiling point.

I hope it helps!

7 0

3 years ago