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AnnZ [28]
3 years ago
11

___ are in group 18

Chemistry
1 answer:
Irina-Kira [14]3 years ago
8 0

Answer:

<h3>a. noble gases</h3>

Explanation:

Groups are numbered 1–18 from left to right. The elements in group 1 are known as the alkali metals; those in group 2 are the alkaline earth metals; those in 15 are the pnictogens; those in 16 are the chalcogens; those in 17 are the halogens; and those in 18 are the noble gases.

Hope this helps

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Balance the following redox equation in acidic solution using the smallest integers possible and select the correct coefficient
romanna [79]

Answer:

Coefficient of H^{+}(aq) is more than 4

Explanation:

Oxidation: Sn^{2+}(aq)\rightarrow Sn^{4+}(aq)

  • Balance charge: Sn^{2+}(aq)-2e^{-}\rightarrow Sn^{4+}(aq)......(1)

Reduction: Cr_{2}O_{7}^{2-}(aq)\rightarrow Cr^{3+}(aq)

  • Balance Cr: Cr_{2}O_{7}^{2-}(aq)\rightarrow 2Cr^{3+}(aq)
  • Balance O and H in acidic medium: Cr_{2}O_{7}^{2-}(aq)+14H^{+}(aq)\rightarrow 2Cr^{3+}(aq)+7H_{2}O(l)
  • Balance charge: Cr_{2}O_{7}^{2-}(aq)+14H^{+}(aq)+6e^{-}\rightarrow 2Cr^{3+}(aq)+7H_{2}O(l).......(2)

[3\times Equation-(1)]+Equation(2) gives balanced equation:

3Sn^{2+}(aq)+Cr_{2}O_{7}^{2-}(aq)+14H^{+}(aq)\rightarrow 3Sn^{4+}(aq)+2Cr^{3+}(aq)+7H_{2}O(l)

So coefficient of H^{+}(aq) is more than 4

3 0
3 years ago
1.86 g H2 is allowed to react with 9.75 g N2 , producing 2.87g NH3.
svet-max [94.6K]

Answer:

                     (a)  Theoretical Yield  =  10.50 g

                      (b)   %age yield  = 27.33 %

Explanation:

Answer-Part-(a)

                 The balance chemical equation for the synthesis of Ammonia is as follow;

                                          N₂ + 3 H₂ → 2 NH₃

Step 1: Calculating moles of N₂ as;

                   Moles = Mass / M/Mass

                   Moles = 9.75 g / 28.01 g/mol

                   Moles = 0.348 moles of N₂

Step 2: Calculating moles of H₂ as;

                   Moles = Mass / M/Mass

                   Moles = 1.86 g / 2.01 g/mol

                   Moles = 0.925 moles

Step 3: Finding Limiting reagent as;

According to equation,

                1 mole of N₂ reacts with  =  3 moles of H₂

So,

             0.348 moles of N₂ will react with  =  X moles of H₂

Solving for X,

                     X = 3 mol × 0.348 mol / 1 mol

                     X = 1.044 mol of H₂

It shows that to consume 0.348 moles of N₂ completely we require 1.044 mol of Hydrogen while, as given in statement we are only provided with 0.925 moles of H₂ hence, hydrogen  is limiting reagent. Therefore, H₂ will control the final yield.

Step 4: Calculating moles of Ammonia as,

According to equation,

                3 mole of H₂ produces  =  2 moles of NH₃

So,

             0.925 moles of H₂ will produce  =  X moles of NH₃

Solving for X,

                     X = 2 mol × 0.925 mol / 3 mol

                     X = 0.616 mol of NH₃

Step 5: Calculating theoretical yield of Ammonia as,

                     Theoretical Yield  =  Moles × M.Mass

                     Theoretical Yield  =  0.616 mol  × 17.03 g/mol

                     Theoretical Yield  =  10.50 g

Answer-Part-(b)

                    %age yield  = Actual Yield / Theoretical Yield × 100

                    %age yield  = 2.87 g / 10.50 g × 100

                    %age yield  = 27.33 %

4 0
3 years ago
Guys- my science teacher doesn't teach, he just says go on schoology ​
Free_Kalibri [48]
The relative mass of each element can be found from the periodic table (the larger number). For instance, P2O5, P = 31.0 O = 16.0, thus the formula mass (Mr) is 2(31) + 5(16) = 142 amu (atomic mass unit). I used a not really specific periodic table. Maybe your teacher is referring to open Schoology (a website where teacher can post files or announcements to students in his or her class). Sorry if i got something mistaken.
5 0
2 years ago
Which of the following is the correct definition of chemical energy?
Anna11 [10]

Answer:

A

Explanation:

energy stored in chemical bonds of molecules

5 0
3 years ago
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The following reaction has an activation energy of 262 kJ/mol.
Hitman42 [59]

Answer: i really       dont know srry

Explanation:

4 0
3 years ago
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