Please help me solve this

How many valence electrons do the alkaline earth metals have?

fenix001 [56]

Answer:

$\boxed{2}$

Explanation:

Alkaline earth metals are in group 2. The number of valence electrons of elements in group 2 is 2.

5 0

3 years ago

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Study this chemical reaction: (aq)(s)(s)(aq) Then, write balanced half-reactions describing the oxidation and reduction that hap

disa [49]

The question is incomplete, complete question is:

Study this chemical reaction:

$FeSO_4 (aq) + Zn (s)\rightarrow Fe (s) + ZnSO_4 (aq)$

Then, write balanced half-reactions describing the oxidation and reduction that happen in this reaction.

Oxidation:

Reduction:

Answer:

Oxidation taking place in given reaction :

$Zn(s)\rightarrow Zn^{2+}+2e^-$

Reduction taking place in given reaction;

$Fe^{2+}(aq)+2e^-\rightarrow Fe(s)$

Explanation:

Redox reaction is defined as the reaction in which oxidation and reduction reaction occur side by side.

Oxidation reaction is defined as the chemical reaction in which an atom looses its electrons. The oxidation number of the atom gets increased during this reaction.

$X\rightarrow X^{n+}+ne^-$

Reduction reaction is defined as the chemical reaction in which an atom gains electrons. The oxidation number of the atom gets reduced during this reaction.

$X^{n+}+ne^-\rightarrow X$

$FeSO_4 (aq) + Zn (s) \rightarrow Fe (s) + ZnSO_4 (aq)$

In the given reaction, iron(II) ions are getting reduced and zinc metal is getting oxidized to zinc(II) ions.

Oxidation :

$Zn(s)\rightarrow Zn^{2+}+2e^-$

Reduction ;

$Fe^{2+}(aq)+2e^-\rightarrow Fe(s)$

6 0

3 years ago

For the reaction below, complete the rate expression that relates the change in concentration with respect to time to the rate o

Ann [662]

Answer: Rate in terms of disappearance of $NO$ = $-\frac{1d[NO]}{2dt}$

Rate in terms of disappearance of $Cl_2$ = $-\frac{1d[Cl_2]}{1dt}$

Rate in terms of appearance of $NOCl$ = $\frac{1d[NOCl]}{2dt}$

Explanation:

Rate law says that rate of a reaction is directly proportional to the concentration of the reactants each raised to a stoichiometric coefficient determined experimentally called as order.

$2NO+Cl_2\rightarrow 2NOCl$

The rate in terms of reactants is given as negative as the concentration of reactants is decreasing with time whereas the rate in terms of products is given as positive as the concentration of products is increasing with time.

Rate in terms of disappearance of = $-\frac{1d[NO]}{2dt}$

Rate in terms of disappearance of = $-\frac{1d[Cl_2]}{1dt}$

Rate in terms of appearance of $NOCl$ = $+\frac{1d[NOCl]}{2dt}$

5 0

3 years ago

If 4.50 l of water vapor at 50.2 °c and 0.121 atm reacts with excess iron, how many grams of iron(iii) oxide will be produced?

Flura [38]

When the balanced equation for this reaction is:
2Fe + 3H2O → Fe2O3 + 3H2

and according to the vapour pressure formula:
PV= nRT
when we have P is the vapor pressure of H2O= 0.121 atm
and V is the volume of H2O = 4.5 L
and T in Kelvin = 52.5 +273 = 325.5 K
R= 0.08205 atm-L/g mol-K
So we can get n H2O
So, by substitution:
n H2O = PV/RT
= (0.121*4.5)/(0.08205 * 325.5) = 0.02038 gmol
n Fe2O3 = 0.02038 * (1Fe2O3/ 3H2O) = 0.00679 gmol
Note: we get (1FeO3/3H2O) ratio from the balanced equation.
we can get the Mass of Fe2O3 from this formula:
Mass = number of moles * molecular weight
when we have a molecular weight of Fe2O3 = 159.7
= 0.00679 * 159.7 = 1.084 g
∴ 1.084 gm of Fe2O3 will produced

6 0

4 years ago

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How do you know the number of valence electrons for those elements?

salantis [7]

Answer:

For neutral atoms, the number of valence electrons is equal to the atom's main group number. The main group number for an element can be found from its column on the periodic table. For example, carbon is in group 4 and has 4 valence electrons. Oxygen is in group 6 and has 6 valence electrons.

Explanation:

hope this help

5 0

3 years ago