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slamgirl [31]
3 years ago
7

20 POINTS 2 QUESTIONS CAN YOU ANSWER THEM ???

Chemistry
2 answers:
Viktor [21]3 years ago
7 0
2. <span>1/8 = (1/2)³ </span>
<span>so it's 3 half lives.</span>
Reika [66]3 years ago
4 0

<u>Answer 1 :</u> The synthesis reaction is, N_2+3H_2\rightarrow 2NH_3

Explanation :

Synthesis reaction : It is a type of reaction in which the reactants present in elemental state react to give a single product.

(1) N_2+3H_2\rightarrow 2NH_3

This is a synthesis reaction.

(2) MgI_2+Br_2\rightarrow MgBr_2+I2

This is a single displacement reaction in which the most reactive element displaces the least reactive element.

(3) KClO_3\rightarrow KCl+O_2

This is a decomposition reaction in which larger reactant decomposes to give two or more products.

(4) HCl+NaOH\rightarrow NaCl+H_2O

This is a neutralization reaction in which an acid and a base react to give a salt and water as a product.

<u>Answer 2 : </u>The number of half-lives it take will be, 3

Formula used :

a=\frac{a_o}{2^n}

where,

a = amount of reactant left after n-half lives = \frac{1}{8}a_o

a_o = Initial amount of the reactant

n = number of half lives

Putting values in above equation, we get:

\frac{1}{8}a_o=\frac{a_o}{2^n}

2^n=8=2^3

n = 3

Therefore, the number of half-lives it take will be, 3

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6. Calculate the mass of an object that has a density of 19.3 g/mL and a volume of 100. mL. (Show Your Work)
Lemur [1.5K]

Answer:

6. mass=1930g

7.64.10ml

Explanation:

6. mass=density time volume

7.volume=mass divide by density

3 0
3 years ago
As an EPA scientist studying catalytic converters and urban smog, you want to find Kc for the following reaction: 2NO2(g) ⇋ N2(g
Bas_tet [7]

Answer:

Kc = 4.774 * 10¹³

Explanation:

the desired reaction is

2 NO₂(g) ⇋ N₂(g) + 2 O₂(g)

Kc =[N₂]*[O₂]² /[NO₂]²

Since

1/2 N₂(g) + 1/2 O₂(g) ⇋ NO(g)

Kc₁= [NO]/(√[N₂]√[O₂]) →  Kc₁²= [NO]²/([N₂][O₂])

and

2 NO₂(g) ⇋ 2 NO(g) + O₂(g)

Kc₂= [NO]²*[O₂]/[NO₂]² →  1/Kc₂= [NO₂]²/([NO]²[O₂])

then

Kc₁²* (1/Kc₂) = [NO]²/([N₂]*[O₂]) *[NO₂]²/([NO]²[O₂])  = [NO₂]²/([N₂]*[O₂]²) = 1/Kc

Kc₁² /Kc₂ = 1/Kc

Kc= Kc₂/Kc₁² =1.1*10⁻⁵/(4.8*10⁻¹⁰)² = 4.774 * 10¹³

3 0
3 years ago
How many moles of Cu(OH)2 are soluble in 1L of sodium hydroxide (NaOH) when the pH is 8.23?
Morgarella [4.7K]

Answer:

4.96E-8 moles of Cu(OH)2

Explanation:

Kps es the constant referring to how much a substance can be dissolved in water. Using Kps, it is possible to know the concentration of weak electrolytes. Then, pKps is the minus logarithm of Kps.

Now, we know that sodium hydroxide (NaOH) is a strong electrolyte, who is completely dissolved in water. Therefore the pH depends only on OH concentration originating from NaOH. Let us to figure out how much is that OH concentration.

pH= -log[H]\\pH= -log (\frac{kw}{[OH]})

8.23 = - log(\frac{Kw}{[OH]} \\10^{-8.23} = Kw/[OH]\\ [OH] = Kw/10^{-8.23}

[OH]=1.69E-6

This concentration of OH affects the disociation of Cu(OH)2. Let us see the dissociation reaction:

Cu(OH)_2 -> Cu^{2+} + 2OH^-

In the equilibrum, exist a concentration of OH already, that we knew, and it will be added that from dissociation, called "s":

The expression for Kps is:

Kps= [Cu^{2+}] [OH]^2

The moles of (CuOH)2 soluble are limitated for the concentration of OH present, according to the next equation.

Kps= s*(2s+1.69E-6)^2

"s" is the soluble quantity of Cu(OH)2.

The solution for this third grade equation is s=4.96E-8 mol/L

Now, let us calculate the moles in 1 L:

moles Cu(OH)_2 = 4.96E-8 mol/L * 1 L = 4.96E-8 moles

7 0
3 years ago
A body was found lying face up in a residence. The body had 4 incised wounds on the trunk centered in the area around the heart
kondaur [170]
Cool what’s the question
7 0
2 years ago
Calculate the mass of butane needed to produce 96.7 g of carbon dioxide
ella [17]
<span>31.9 grams butane needed to produce 96.7 grams CO2

</span>
5 0
3 years ago
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