One mole of a substance contains 6.02×10∧23 particles,
1 mole of a aluminium contains 27 g
35 g of aluminium contains 35/27 =1.296 moles
Thus, the number of particles will be 1.296 × 6.02 ×10∧23
= 7.804 × 10∧23 particles,
Hence, 35 g of Aluminium contains 7.804 × 10∧23 atoms
Answer:
0.393 mol/L.
Explanation:
The following data were obtained from the question:
Number of mole of NaOH = 0.550 mol
Volume of solution = 1.40 L
Molarity of NaOH =.?
Molarity of a solution is simply defined as the mole of solute per unit litre of the solution. Mathematically, it is expressed as:
Molarity = mole /Volume
With the above formula, we can obtain the molarity of the NaOH solution as follow:
Number of mole of NaOH = 0.550 mol
Volume of solution = 1.40 L
Molarity of NaOH =.?
Molarity = mole / Volume
Molarity of NaOH = 0.55 / 1.4
Molarity of NaOH = 0.393 mol/L
Thus, the molarity of the NaOH solution is 0.393 mol/L.
<u>Answer:</u> The mass of second isotope of indium is 114.904 amu
<u>Explanation:</u>
Average atomic mass of an element is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.
Formula used to calculate average atomic mass follows:
.....(1)
Let the mass of isotope 2 of indium be 'x'
Mass of isotope 1 = 112.904 amu
Percentage abundance of isotope 1 = 4.28 %
Fractional abundance of isotope 1 = 0.0428
Mass of isotope 2 = x amu
Percentage abundance of isotope 2 = [100 - 4.28] = 95.72 %
Fractional abundance of isotope 2 = 0.9572
Average atomic mass of indium = 114.818 amu
Putting values in equation 1, we get:
![114.818=[(112.904\times 0.0428)+(x\times 0.9572)]\\\\x=114.904amu](https://tex.z-dn.net/?f=114.818%3D%5B%28112.904%5Ctimes%200.0428%29%2B%28x%5Ctimes%200.9572%29%5D%5C%5C%5C%5Cx%3D114.904amu)
Hence, the mass of second isotope of indium is 114.904 amu
The oxidation state of Chromium chloride (III) is +3
How can we find the answer?
First of all write down what you know about the molecule:
1: The molecule hasn't got an electric charge (is not an ione), this means that either positive and negative charges of its atoms are balanced (we have the same number of positve and negative charges)
2: Since it's a salt, where the metal is chromium and the non metal is the alogen Chlorine, we know that the negative charge belogns to the non metal element because of its elettronegativity, therefore the positive charge belongs to the metale element (chromium).
3: when chlorin forms binary salts its oxidation state is always -1 (you can find out this info in a periodic table)
In <span>CrC<span>l3</span></span> we have 3 chlorine atoms where each of them carrys 1 negative charge, so the total amount of negative charges is -3
Since the charges are balanced, the question is: Which is the positive charge that Chromium must carry in order to balance 3 negative charges?
The answer comes out to +3
Answer:
7.3 g (NH₄)₃PO₄
Explanation:
The balanced equation for the reaction is:
H₃PO₄ + 3 NH₃ ----> (NH₄)₃PO₄
To find the mass of ammonium phosphate ((NH₄)₃PO₄) produced, you need to (1) convert grams NH₃ to moles NH₃ (via the molar mass from the periodic table), then (2) convert moles NH₃ to moles (NH₄)₃PO₄ (via mole-to-mole ratio from balanced equation), and then (3) convert moles (NH₄)₃PO₄ to grams (NH₄)₃PO₄ (via molar mass from periodic table). Make sure to arrange the ratios/conversions in a way that allows for the cancellation of units. The final answer should have 2 sig figs because the given value (2.5 grams) has 2 sig figs.
Molar Mass (NH₃): 14.01 g/mol + 3(1.008 g/mol)
Molar Mass (NH₃): 17.034 g/mol
Molar Mass ((NH₄)₃PO₄):
3(14.01 g/mol) + 12(1.008 g/mol) + 30.97 g/mol + 4(16.00 g/mol)
Molar Mass ((NH₄)₃PO₄): 149.096 g/mol
2.5 g NH₃ 1 mole NH₃ 1 mole (NH₄)₃PO₄ 149.096 g
--------------- x -------------------- x --------------------------- x --------------------------
17.034 g 3 moles NH₃ 1 mole (NH₄)₃PO₄
= 7.3 g (NH₄)₃PO₄
