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2 years ago

An element with the electron configuration [xe] 6s24f145d7 would belong to which class on the periodic table?

1 answer:

8 0

If the atom is neutral then, the total number of electrons is the same as the number of protons. We calculate for the total number of electrons given the compressed electron configuration,
number of electrons of Xenon (Xe) = 54
The total number of electrons after Xenon,
= 2 + 14 + 7 = 23

Adding up all the number of electrons, we have,
total number of electrons = 54 + 23 = 77

The identity of this element is Iridium (Ir). This element belongs to the class of Group 9. This is the transition metal.

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Wine has a pH of 3, which means it is __________ times more acidic than tomatoes, which have a pH of 4.

Natasha2012 [34]

Answer:

Explanation:

pH is defined as the negative logarithm of the concentration of hydrogen ions.

Thus,

pH = - log [H⁺]

Thus, from the formula, more the concentration of the hydrogen ions or more the acidic the solution is, the less is the pH value of the solution.

Thus, solution with pH = 3 will be more acidic than solution with pH =4

Thus, concentration of the [H⁺] when pH =3

3 = - log [H⁺]

[H⁺] = 10⁻³ M

For pH = 4, [H⁺] = 10⁻⁴ M

<u>hence, pH = 3 is 10 times more acidic than pH = 4</u>

5 0

2 years ago

A 50.0 mL sample of 0.600 M calcium hydroxide is mixed with 50.0 mL sample of 0.600 M hydrobromic acid in a Styrofoam cup. The t

TEA [102]

Explanation:

The reaction equation will be as follows.

$Ca(OH)_{2}(aq) + 2HBr(aq) \rightarrow CaBr_{2}(aq) + 2H_{2}O(l)$

So, according to this equation, 1 mole $Ca(OH)_{2}$ = 2 mol HBr = 1 mol $CaBr_{2}$

Therefore, calculate the number of moles of calcium hydroxide as follows.

No. of moles of $Ca(OH)_{2}$ = $V \times Molarity$

= $50 \times 0.6$

= 30 mmol

Similarly, calculate the number of moles of HBr as follows.

No. of moles of HBr = $M \times V$

= $50 \times 0.6$

= 30 mmol

This means that the limiting reactant is HBr.

So, no. of moles of $CaBr_{2}$ = $30 \times \frac{1}{2}$

= 15 mmol

Hence, calculate the amount of heat released as follows.

Heat released in the reaction(q) = $m \times s \times \Delta T$

as, m = mass of solution

and, Density = $\frac{mass}{volume}$

or, mass = Density × Volume

= 1.08 g/ml \times (50 + 50) ml

= 108 g

where, s = specific heat of solution = 4.18 j/g.k

and, change in temperature $\Delta T$ = $(26 - 23)^{o}C$

= $3
^{o}C$

Hence, the heat released will be as follows.

q = $m \times s \times \Delta T$

q = $108 \times 4.18 \times 3^{o}C$

= 1354.32 joule

or, = 1.354 kJ (as 1 kJ = 1000 J)

Also, $\Delta H_{rxn}$ = $\frac{-q}{n}$

= $\frac{-1.354}{15 \times 10^{-3}}$

= -90.267 kJ/mol

Thus, we can conclude that the enthalpy change for the given reaction is -90.267 kJ/mol.

6 0

2 years ago

Which statement is true of a reversible reaction at equilibrium?

Vedmedyk [2.9K]

Answer:

The concentration of reactants and the concentration of products are constant.

Explanation:

pls mark as brainliest

7 0

2 years ago

Read 2 more answers

Which of the following statements concerning hydrocarbons is/are correct?

Alona [7]

Answer:

1. Saturated hydrocarbons may be cyclic or acyclic molecules.

2. An unsaturated hydrocarbon molecule contains at least one double bond.

Explanation:

Hello,

In this case, hydrocarbons are defined as the simplest organic compounds containing both carbon and hydrogen only, for that reason we can immediately discard the third statement as ethylenediamine is classified as an amine (organic chain containing NH groups).

Next, as saturated hydrocarbons only show single carbon-to-carbon bonds and carbon-to-hydrogen bonds, they may be cyclic (ring-like-shaped) or acyclic (not forming rings), so first statement is true

Finally, since we can find saturated hydrocarbons which have single carbon-to-carbon and carbon-to-hydrogen bonds only and unsaturated hydrocarbons which could have double or triple bonds between carbons and carbon-to-hydrogen bonds, the presence of at least one double bond makes the hydrocarbon unsaturated.

Therefore, first and second statements are correct.

Best regards.

6 0

2 years ago

When iron pyrite (FeS2) is heated in air, the process known as "roasting" forms sulfur dioxide and iron(III) oxide. When the equ

Ronch [10]

Answer:

The coefficient of O2 is 11

Explanation:

Step 1:

The equation for the reaction:

FeS2 + O2 → SO2 + Fe2O3

Step 2:

Balancing the equation. The equation can be balance as follow:

FeS2 + O2 → SO2 + Fe2O3

There are 2 atoms of Fe on the right side and 1 atom on the left. It can be balance by putting 2 in front of FeS2 as shown below:

2FeS2 + O2 → SO2 + Fe2O3

There are 4 atoms of S on the left side and 1 atom on the right side. It can be balance by putting 4 in front of SO2 as shown below:

2FeS2 + O2 → 4SO2 + Fe2O3

Now, there are a total of 11 atoms of O on the right side and 2 atoms on the left side. It can be balance by putting 11/2 in front of O2 as shown below:

2FeS2 + 11/2O2 → 4SO2 + Fe2O3

Multiply through by 2 to clear the fraction as shown below:

4FeS2 + 11O2 → 8SO2 + 2Fe2O3

Now the equation is balanced.

The coefficient of O2 is 11

8 0

2 years ago