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3 years ago

HELP ME QUICK

Chemistry

2 answers:

kozerog [31]3 years ago

5 0

The answer is A. Heat is released.

I hope that this helps!

Sophie [7]3 years ago

3 0

Quick answer: Exothermic reactions mean that heat has escaped the system. The answer is A. Heat is released.

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How many moles contain 5.34 x 10^26 atoms of iron?

SCORPION-xisa [38]

Answer: 1.31 × 10^47 sorry if its not the answer

Explanation:

6 0

2 years ago

The acid dissociation constant Ka of boric acid (H3BO3) is 5.8 times 10^-10. Calculate the pH of a 4.4 M solution of boric acid.

madam [21]

Answer: The pH of a 4.4 M solution of boric acid is 4.3

Explanation:

$H_3BO_3\rightarrow H^+H_2BO_3^-$

at t=0 cM 0 0

at eqm $c-c\alpha$ $c\alpha$ $c\alpha$

So dissociation constant will be:

$K_a=\frac{(c\alpha)^{2}}{c-c\alpha}$

Give c= 4.4 M and $\alpha$ = ?

$K_a=5.8\times 10^{-10}$

Putting in the values we get:

$5.8\times 10^{-10}=\frac{(4.4\times \alpha)^2}{(4.4-4.4\times \alpha)}$

$(\alpha)=0.000011$

$[H^+]=c\times \alpha$

$[H^+]=4.4\times 0.000011=4.8\times 10^{-5}M$

Also $pH=-log[H^+]$

$pH=-log[4.8\times 10^{-5}]=4.3$

Thus pH of a 4.4 M $H_3BO_3$ solution is 4.3

3 0

3 years ago

What type of plate boundary would form where there is a mountain range present, known earthquake activity, but no trenches prese

Natasha_Volkova [10]

Answer:

continental-continental convergent boundary

Explanation:

When two continental plates converge, they smash together and create mountains. The amazing Himalaya Mountains are the result of this type of convergent plate boundary. The Appalachian Mountains resulted from ancient convergence when Pangaea came together.

5 0

3 years ago

In a chemical reaction, 28g of iron reacts with 16g of sulfur to produce _________ of iron sulfide.

kirill115 [55]

Hello!

In a chemical reaction, 28g of iron reacts with 16g of sulfur to produce _________ of iron sulfide.

We have the following data:

m(Fe) - mass of iron = 28 g

m(S) - mass of sufur = 16 g

MM(Fe) - molar mass of iron ≈ 56 g/mol

MM(S) - molar mass of sulfur ≈ 32 g/mol

n(Fe) - number of mol of iron = ?

n(S) - number of mol of sulfur = ?

Solving:

* to n(Fe)

$n_{Fe} = \dfrac{m_{Fe}}{MM_{Fe}}$

$n_{Fe} = \dfrac{28\:\diagup\!\!\!\!\!g}{56\:\diagup\!\!\!\!\!g/mol}$

$\boxed{n_{Fe} = 0.5\:mol}$

* to n(S)

$n_{S} = \dfrac{m_{S}}{MM_{S}}$

$n_{S} = \dfrac{16\:\diagup\!\!\!\!\!g}{32\:\diagup\!\!\!\!\!g/mol}$

$\boxed{n_{S} = 0.5\:mol}$

The stoichiometric reaction will be in the same proportion (1 : 1), let us see:

$Fe + S \Longrightarrow FeS$

1 mol of Fe -------------- 1 mol of FeS

0.5 mol of Fe ------------ 0.5 mol of FeS

Will the reaction of the iron mass with the mass of sulfur produce how many grams of iron sulfide? We will see:

n(FeS) - number of mol of iron sulfide = 0.5 mol

m(FeS) - mass of iron sulfide = ? (in grams)

MM(FeS) - Molar Mass of iron sulfide = 56 + 32 = 88 g/mol

Solving:

$n_{FeS} = \dfrac{m_{FeS}}{MM_{FeS}}$

$m_{FeS} = n_{FeS}*MM_{FeS}$

$m_{FeS} = 0.5\:mol\!\!\!\!\!\!\!\!\!\!\!\dfrac{\hspace{0.6cm}}{~}*88\:\dfrac{g}{mol\!\!\!\!\!\!\!\!\!\!\!\dfrac{\hspace{0.6cm}}{~}}$

$\boxed{\boxed{m_{FeS} = 44\:g}}\:\:\:\:\:\:\bf\blue{\checkmark}\bf\green{\checkmark}\bf\red{\checkmark}$

Answer:

44 grams of iron sulfide

___________________________

$\bf\red{I\:Hope\:this\:helps,\:greetings ...\:Dexteright02!}\:\:\ddot{\smile}$

4 0

2 years ago

A glass column is filled with mercury and inverted in a pool of mercury. The mercury column stabilizes at a height of 729 mm abo

harkovskaia [24]

The atmospheric pressure will be:

The pressure of the atmosphere resulting from the mercury column is 0.959 atm

What is atmospheric pressure?

The force that an object experiences from the weight of the air above it per unit area are known as atmospheric pressure.

Given: Height of mercury column = 729 mm Hg

To find: The pressure of the atmosphere

Calculation:

The atmospheric column resulting from the mercury column is calculated as follows:

1 atm =760 mm Hg

So, we can convert the 729 mm Hg to atm, and we get

Atmospheric pressure = 729 x 1 atm / 760 = 0.959 atm

Learn more about atmospheric pressure here,

brainly.com/question/14315894

#SPJ4

5 0

1 year ago