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3 years ago

10

Josh prepares a solution by mixing sodium nitrate and water. To calculate the molarity of the solution, Josh should calculate th

e moles of which substance, and why?

1 answer:

Sauron [17]3 years ago

3 0

Of the sodium nitrate as molarity of a solution is expressed as the number of moles of a given substance per 1000cm3 or 1dm3 of water
hope that helps

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(6 points) Calculate the maximum number of moles and grams of H2S that can form when 158 g of aluminum sulfide reacts with 131 g

Schach [20]

Answer:107.1 g, 124.1 g

Explanation:

The equation of the reaction is;

Al2S3(s) + 6H20(l) ----> 2Al(OH)3(s) + 3H2S(g)

Hence;

For Al2S3

Number of moles= reacting mass/molar mass

Number of moles = 158g/150gmol-1 =1.05 moles

If 1 mole of Al2S3 yields 3 moles of H2S

1.05 moles of Al2S will yield

1.05 × 3/1 = 3.15 moles

Mass of H2S = 3.15moles × 34 gmol-1 = 107.1 g

For water

Number of moles of water = 131g/18gmol-1= 7.3 moles

6 moles of water yields 3 moles of H2S

7.3 moles of water will yield 7.3 × 3/6 = 3.65 moles of H2S

3.65 moles × 34 gmol-1 =124.1 g

5 0

3 years ago

Which or these equations is balanced H2SO4 + 2Al > Al2(SO4)3 + H2 or 2KCl + Pb(NO3)2 > 2KNO3 + PbCl2

Dmitry_Shevchenko [17]

Balancing of chemical equation is essential because of the law of conservation of mass, which states that the mass of a system can not be created or removed.

The second equation is balanced

$2KCl_(_a_q_) +Pb(NO_3)_2_(_a_q_) ==> 2KNO_3_(-a_q_) + PbCl_2(_a_q_)$

This is because the number of elements of each atom in the product side equal the number of elements of each atom on the reactant side.

The first equation is not balanced

$H_2SO_4 _(_a_q) + 2Al_(_s_) ==> Al(SO_4)_3_(_a_q_) + H_2_(_g_)$

This is because there is 1 molecule of $SO_4^{-2}$ on reactant side as compared to 3 molecules of $SO_4^{-2}$

To balance the equation we add a coefficient of 3 on sulphuric acid ( $H_2SO_4$ ) and a coefficient of 3 on hydrogen ( $H_2$ )

$3H_2SO_4_(_a_q_) + 2Al_(_s_) ==> Al(SO_4)_3_(_a_q_) + 3H_2_(_g_)$

7 0

3 years ago

Copper is an example of a(n) __________.

navik [9.2K]

The answer is D. element

It's not a mixture, just a pure element. Copper (Cu) is found on the Periodic Table of the Elements, where only ELEMENTS are organized.

7 0

3 years ago

Read 2 more answers

PLEASEEEEEE HELPPPP???

Elenna [48]

1. c
2. a
3. a
(I’m not 100% but 2 & 3 couldn’t be transform)

4 0

2 years ago

1.505 times 10^23 Na atoms

dybincka [34]

5.75g

Explanation:

Given parameters:

Number of atoms = 1.505 x 10²³atoms

let us find the number of moles and mass of this atom.

Solution:

The mole is convenient unit for reporting measurements in chemistry. It allows us to make mathematical calculations:

one mole of substance contains 6.02 x 10²³atoms

Number of moles of Na given = $\frac{1.505 x 10^{23} }{6.02 x 10^{23} }$ = 0.25moles

Mass of Na atom given = number of moles x molar mass

Molar mass of Na= 23g/mole

Mass of Na = 0.25 x 23 = 5.75g

learn more:

Number of moles brainly.com/question/1841136

#learnwithBrainly

8 0

2 years ago