Wat happens when water is added to a sand-salt mixture ?

____ [38]

Answer:

Evaporation from the hydrosphere provides the medium for cloud and rain formation in the atmosphere. The atmosphere brings back rainwater to the hydrosphere. The atmosphere provides the geosphere with heat and energy needed for rock breakdown and erosion. The geosphere, in turn, reflects the sun's energy back into the atmosphere.

Explanation:

4 0

3 years ago

Analyze: The metallic character of an element is determined by how readily it loses electrons. Elements that lose electrons most

GenaCL600 [577]

Answer:

Group 1 or akali metals have the greatest metallic property.

Group 17 has the lowest metallic character.

C. As you move from right to lefton the periodic table, metallic character increases which is the ability to lose electrons. Ionization energy decrease as we move from right to left on the periodic table.

Explanation:

Akali metals in group 1 have the greatest metallic property and they are the most reactive metals. Francium metal on the group has the most metallic characteristics. It is rare and very radioactive. Group 17 has the lowest metallic character. This is because while moving across the period, the number of electrons in the outermost shell increases. This make it difficult for atoms to leave see electrons and become electropositive . Group 17 has the highest tendency of accepting electrons.

Ionization energy is the energy use to remove electron from an atom in gaseous stage. Ionization energy decrease as we move from right to left on the periodic table and metallic character increases as we move from right to left on the periodic table.

5 0

3 years ago

Over the years, the thermite reaction has been used for welding railroad rails, in incendiary bombs, and to ignite solid-fuel ro

melamori03 [73]

Answer: The mass of nickel (II) oxide and aluminium that must be used is 18.8 g and 4.54 g respectively.

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ .....(1)

For nickel:

Given mass of nickel = 14.8 g

Molar mass of nickel = 58.7 g/mol

Putting values in equation 1, we get:

$\text{Moles of nickel}=\frac{14.8g}{58.7g/mol}=0.252mol$

For the given chemical reaction:

$3NiO(s)+2Al(s)\rightarrow 3Ni(l)+Al_2O_3(s)$

For nickel (II) oxide:

By Stoichiometry of the reaction:

3 moles of nickel are produced from 3 moles of nickel (II) oxide

So, 0.252 moles of nickel will be produced from $\frac{3}{3}\times 0.252=0.252mol$ of nickel (II) oxide

Now, calculating the mass of nickel (II) oxide by using equation 1:

Molar mass of nickel (II) oxide = 74.7 g/mol

Moles of nickel (II) oxide = 0.252 moles

Putting values in equation 1, we get:

$0.252mol=\frac{\text{Mass of nickel (II) oxide}}{74.7g/mol}\\\\\text{Mass of nickel (II) oxide}=(0.252mol\times 74.7g/mol)=18.8g$

For aluminium:

By Stoichiometry of the reaction:

3 moles of nickel are produced from 2 moles of aluminium

So, 0.252 moles of nickel will be produced from $\frac{2}{3}\times 0.252=0.168mol$ of aluminium

Now, calculating the mass of aluminium by using equation 1:

Molar mass of aluminium = 27 g/mol

Moles of aluminium = 0.168 moles

Putting values in equation 1, we get:

$0.168mol=\frac{\text{Mass of aluminium}}{27g/mol}\\\\\text{Mass of aluminium}=(0.168mol\times 27g/mol)=4.54g$

Hence, the mass of nickel (II) oxide and aluminium that must be used is 18.8 g and 4.54 g respectively.

4 0

3 years ago

Whoever awser correct I will give you Brainly

vivado [14]

Answer:

Option A.

2Na + 2H2O —> 2NaOH + H2

Explanation:

To know which option is correct, we shall do a head count of the number of atoms present on both side to see which of them is balanced. This is illustrated below below:

For Option A:

2Na + 2H2O —> 2NaOH + H2

Reactant >>>>>>> Product

2 Na >>>>>>>>>>> 2 Na

4 H >>>>>>>>>>>> 4 H

2 O >>>>>>>>>>>> 2 O

Thus, the above equation is balanced.

For Option B:

2Na + 2H2O —> NaOH + H2

Reactant >>>>>>> Product

2 Na >>>>>>>>>>> 1 Na

4 H >>>>>>>>>>>> 3 H

2 O >>>>>>>>>>>> 1 O

Thus, the above equation is not balanced.

For Option C:

2Na + H2O —> 2NaOH + H2

Reactant >>>>>>> Product

2 Na >>>>>>>>>>> 2 Na

2 H >>>>>>>>>>>> 4 H

1 O >>>>>>>>>>>> 2 O

Thus, the above equation is not balanced.

For Option D:

Na + 2H2O —> NaOH + 2H2

Reactant >>>>>>> Product

1 Na >>>>>>>>>>> 1 Na

4 H >>>>>>>>>>>> 5 H

2 O >>>>>>>>>>>> 1 O

Thus, the above equation is not balanced.

From the illustrations made above, only option A is balanced.

7 0

3 years ago

For the reaction 2NOCl(g) <-----> 2NO(g) + Cl2(g), Kc = 8.0 at a certain temperature. What concentration of NOCl must be p

Nat2105 [25]

Answer is: concentration of NOCl is 3.52 M.

Balanced chemical reaction: 2NOCl(g) ⇄ 2NO(g) + Cl₂(g).
Kc = 8.0.
[NOCl] = 1.00 M; equilibrium concentration.
[NO] = x.
[Cl₂] = x/2; equilibrium concentration of chlorine.
Kc = [Cl₂] ·[NO]² / [NOCl].
8.00 = x/2 · x² / 1.
x³/2 = 8.
x = ∛16.
x = 2.52 M.
co(NOCl) = [NOCl] + x.
co(NOCl) = 1.00 M + 2.52 M.
co(NOCl) = 3.52 M; the initial concentration of NOCl.

7 0

3 years ago