Answer:
The mass of the element is 26.20 amu
Explanation:
In this question, we are asked to calculate the mass of an element with 15 protons, 13 electrons and 11 neutrons
To calculate the atomic mass of the element, we take into consideration the masses of the individual sub atomic particles
Electrons have 0 atomic mass unit(their masses are negligible) we have no business here, Protons have a mass of
1.00727647 amu, while the mass of neutron is 1.0086654 amu
The mass of 15 protons is thus 15 * 1.00727647 = 15.10914705 amu
The mass of 11 neutrons is 11 * 1.0086654 =
11.0953194 amu
Adding this together, we have ; 11.0953194 + 15.10914705 = approximately 26.20 amu
como se denomina el proceso utilizado para descomponer el agua
Answer:
you must add 50 mL
Explanation:
Hi
KOH is a strong base and by adding 100mL 0.05M you will have an amount of 5 millimol.
NaCN is a base and by adding 50 mL 0,150 M you will have an amount of 7,5 mmol.
HCl is a acid and by adding 200 mL 0,075 M you will have an amount of 15 mmol.
The acid reacts with the bases leaving 2.5 mmol unreacted.
Na3PO4 is a base and by adding 50 mL 0,1 M you will have an amount of 5 mmol.
The 2.5 mmol of acid react with the base PO4 ^ -3 forming a regulatory solution of PO4 ^ -3 and HPO4 ^ -2 of pKa 2.12
5 mmol of acid (HNO3) must be added to obtain a regulatory solution formed by the same amount of HPO4 ^ -2 (2.5 mmol) and H2PO4 ^ -1 (2.5 mmol) with pKa 7.21
Considering a quantity of 5 mmol of HNO3 of concentration 0.1 M, 50 mL must be added.
To calculate the pH of the regulatory solution you should consider pH = pKa × Ca / Cb pH = 7.21 × 2.5 / 2.5 = 7.21 Being in the same solution the volume is the same and can be simplified to achieve a faster calculation.
successes with your homework
Atoms are the unit of the molecule of the compound. The 3.01 x 10²⁴ atoms of oxygen are present in 5 moles of water and 3 moles of carbon dioxide in the sample.
<h3>What are atoms?</h3>
Atoms are the smallest fundamental unit of the compounds that can be given by Avogadro's number.
For calculating the oxygen atoms in 5 mole water:
If 1 mole = 6.02 × 10²³
Then, 5 moles = 5 × 6.02 × 10²³
Hence, 3.01 x 10²⁴ atoms of oxygen are present in 5 moles of water.
Moles of carbon dioxide in the sample is calculated as:
If 1 mole of carbon dioxide = 6.02 × 10²³ molecules
Then moles in 1.8 x 10²⁴ molecules will be,
(1.8 x 10²⁴ molecules) ÷ (6.02 × 10²³ molecules) = 3 moles
Hence, 3 moles of carbon dioxide is present in the sample.
Learn more about Avogadro's number here:
brainly.com/question/5098076
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CuO(aq) + H2(g) → H2O(l) + Cu(s)
CuO= 64 + 16= 80g
1 mole of CuO → 1 mole of Cu
80g of CuO → 1 mole of Cu
20.50g of CuO → y
y= 20.50/80= 0.26mole.
