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4 years ago

How do you know if a reaction is exothermic?

1 answer:

n200080 [17]4 years ago

3 0

You know if the reaction releases energy or heat.

Info:
<span>An exothermic reaction is a chemical reaction that releases energy by light or heat. It is the opposite of an endothermic reaction. Expressed in a chemical equation: reactants → products + energy.</span>

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A sample of 0.600 mol of a metal M reacts completely with excess fluorine to form 46.8 g of MF2.?

harkovskaia [24]

Answer:

See Explanation

Explanation:

Given:

moles M = 0.600 mole

moles F = excess (for rxn stoichiometry)

Formula Weight (F.Wt.) of F = 19 grams/mole (from Periodic Table)

Yield in grams = 46.8 grams (assuming theoritical yield)

Rxn: M + F₂ => MF₂

0.600mol Excess 0.600mol (1:1 rxn ratio for M:MF₂)

a. moles of F in MF₂ = 2(0.600) moles F = 1.2 moles F

b. mole weight MF₂ = 46.8g/0.600mol = 78g/mole

F.Wt. MF₂ = F.Wt. M + 2(F.Wt. F)

=> mass M = F.Wt. M = [F.Wt. MF₂ - 2(F.Wt. F)] = 78g/mol. - 2(19g/mol.)

= (78 - 38) grams/mole = 40 grams/mole

c. Calcium (Ca) has F.Wt. = 40 grams/mole (compared to Calcium on Periodic Table.

4 0

3 years ago

Which set of numbers gives the correct possible values of I for n = 22

Alexandra [31]

Answer:

Hello friends

Explanation:

<h3>For a given principal quantum number for or n, the corresponding angular quantum number or is equivalent to a range between 0 and( n-1)</h3>

<h3>This means that the angular quantum number for a principal quantum number of 2 is equivalent to.</h3>

<h3>Hope it's helpfully. </h3>

4 0

3 years ago

Which statement best describes how protons were

Sonja [21]

Answer:

Explanation:

7 0

3 years ago

Is mixing salt and pepper physical change or chemical change ?

Rom4ik [11]

Yes mixing salt with pepper change

6 0

3 years ago

In this reaction, what roll does the lead (II) nitrate play when 50.0 mL of 0.100M iron (III) chloride are mixed with 50.0 mL of

Aloiza [94]

Answer: The roll of lead (II) nitrate is that it is a limiting reactant of the reaction.

Solution : Given,

Molarity of $FeCl_3$ = 0.1 M

Volume of $FeCl_3$ = 50.0 ml = 0.05 L (1 L = 1000 ml)

Molarity of $Pb(NO_3)_2$ = 0.1 M

Volume of $Pb(NO_3)_2$ = 50.0 ml = 0.05 L

First we have to calculate the moles of $FeCl_3$ and $Pb(NO_3)_2$ .

$\text{ Moles of }FeCl_3=\text{ Molarity}\times \text{ Volume in L}$

$\text{ Moles of }FeCl_3=(0.100M)\times (0.05L)=0.005moles$

$\text{ Moles of }Pb(NO_3)_2=\text{ Molarity}\times \text{ Volume in L}$

$\text{ Moles of }Pb(NO_3)_2=(0.100M)\times (0.05L)=0.005moles$

The balanced chemical reaction is,

$2FeCl_3+3Pb(NO_3)_2\rightarrow 2Fe(NO_3)_3+3PbCl_2$

From the balanced chemical equation, we conclude that

3 moles of lead nitrate react with 2 moles of ferric chloride.

Thus 0.005 moles of lead nitrate react with $=\frac{2}{3}\times 0.005=0.0033$ moles of ferric chloride.

Moles of ferric chloride will be left unreacted = 0.005 - 0.0033 =0.0017 moles

Limiting reagent is the reagent in the reaction which limits the formation of product.

Excess reagent is the reagent in the reaction which is in excess and thus remains unreacted.

Therefore, in the given reaction, lead nitrate is the limiting reagent and ferric chloride is the excess reagent.

7 0

3 years ago

Read 2 more answers