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makvit [3.9K]
3 years ago
5

Please help. Last grade of this class

Chemistry
1 answer:
Marat540 [252]3 years ago
5 0

Answer: Question 3

Group 14, Period 3 is a metalloid

Explanation: Question 3

The element in group 14, period 3 on the periodic table is Si. Metalloids are elements which share both non-metallic and metallic characteristics.

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Is there an N−Cl bond in solid ammonium chloride?
Tems11 [23]
When ammonia is reacted with HCl it abstracts proton from acid and forms Ammonium Ion and Chloride Ion.

                              NH₃  +  HCl   →   ⁺NH₄  + Cl⁻ (simply Written NH₄Cl)
Structure,
              The structure of Ammonium Chloride is among those structures which contains all three types of bonding's, i.e.
                                  
                                                Ionic Bond

                                                Covalent Bond

                                                Coordinate Covalent Bond

Three Hydrogen atoms previously bonded with Nitrogen are covalent in nature. The new incoming proton from HCl forms co-ordinate covalent bond with Nitrogen and Chloride Ion containing negative charge make Ionic Bond with the positive Ammonium Ion. In question, if the line between Nitrogen and Chlorine atom is assumed covalent then it is incorrect. Structure is shown below,

5 0
3 years ago
Which represents the self ionization of water at 25 degrees
gayaneshka [121]
This question comes with four answer choices:

<span>A. H2O + H2O ⇄ 2H2 + O2

B. H2O + H2O⇄  H2O2 + H2

C. H2O + H2O ⇄ 4H+ + 2O2-

D. H2O + H2O ⇄  H3O+ + OH-

Answer: option </span><span>D. H2O + H2O ⇄  H3O+ + OH-

(the +sign next to H3O is a superscript, as well as the - sing next to OH)

Explanation:

The self-ionization of water, or autodissociation, produces the two ions H3O(+) and OH(-). The presence of ions is what explain the electrical conductivity of pure water.

</span><span>In this, one molecule of H2O loses a proton (H+) (deprotonates) to become a hydroxide ion, OH−. Then, he <span>hydrogen ion, H+</span>, immediately protonates another water molecule to form hydronium, H3O+.
</span>
7 0
3 years ago
How many kilojoules of energy would be required to heat a 225g block of aluminum from 23.0 C to 73.5 C?
gulaghasi [49]

Answer:

\boxed {\boxed {\sf 10.2 \ kJ}}

Explanation:

We are asked to find how many kilojoules of energy would be required to heat a block of aluminum.

We will use the following formula to calculate heat energy.

q=mc \Delta T

The mass (m) of the aluminum block is 225 grams and the specific heat (c) is 0.897 Joules per gram degree Celsius. The change in temperature (ΔT) is the difference between the final temperature and the initial temperature.

  • ΔT = final temperature - inital temperature

The aluminum block was heated from 23.0 °C to 73.5 °C.

  • ΔT= 73.5 °C - 23.0 °C = 50.5 °C

Now we know all three variables and can substitute them into the formula.

  • m= 225 g
  • c= 0.897 J/g° C
  • ΔT= 50.5 °C

q= (225 \ g )(0.897 \ J/g \textdegree C)(50.5 \textdegree C)

Multiply the first two numbers. The units of grams cancel.

q= (225 \ g  * 0.897 \ J/g \textdegree C)(50.5 \textdegree C)

q= (225   * 0.897 \ J / \textdegree C)(50.5 \textdegree C)

q= (201.825\ J / \textdegree C)(50.5 \textdegree C)

Multiply again. This time, the units of degrees Celsius cancel.

q= 201.825 \ J * 50.5

q= 10192.1625 \ J

The answer asks for the energy in kilojoules, so we must convert our answer. Remember that 1 kilojoule contains 1000 joules.

\frac { 1  \ kJ}{ 1000 \ J}

Multiply by the answer we found in Joules.

10192.1625 \ J * \frac{ 1 \ kJ}{ 1000 \ J}

10192.1625  * \frac{ 1 \ kJ}{ 1000 }

\frac {10192. 1625}{1000} \ kJ

10.1921625 \ kJ

The original values of mass, temperature, and specific heat all have 3 significant figures, so our answer must have the same. For the number we found, that is the tneths place. The 9 in the hundredth place tells us to round the 1 up to a 2.

10.2 \ kJ

Approximately <u>10.2 kilojoules</u> of energy would be required.

3 0
3 years ago
What type of isomerism is shown by alkanes
Luda [366]

Answer:

Alkanes with more than 3 carbons can show constitutional isomerism. They can be either linear or branched structures. This is categorized as chain isomerism. Butane is the smallest alkane to show such isomerism with 2 isomers.Alkanes with more than 3 carbons can show constitutional isomerism. They can be either linear or branched structures. This is categorized as chain isomerism. Butane is the smallest alkane to show such isomerism with 2 isomers.

Explanation:

6 0
3 years ago
Father, I come to you worn and weary from the hard times I have walked through recently. I come to you seeking your shelter wher
Ganezh [65]

Answer:

Fact: There’s only one letter that doesn’t appear in any U.S. state name

And that is Q

Explanation:

8 0
3 years ago
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