Answer:
2.38x10²³ atoms oxygen
Explanation:
To solve this question we need to convert the mass of sand to moles using its molar mass (Molar mass SiO₂ = 60.08g/mol). Twice these moles are the moles of Oxygen and using Avogadro's number we can find the amount of atoms of Oxygen in the mixture:
<em>Moles SiO₂:</em>
11.87g * (1mol / 60.08g) = 0.1976moles SiO₂
<em>Moles Oxygen:</em>
0.1976moles SiO₂* 2 = 0.3951moles oxygen
<em>Atoms oxygen:</em>
0.3951moles oxygen * (6.022x10²³atoms / 1mol O₂) =
<h3>2.38x10²³ atoms oxygen</h3>
Answer:- Octet of NO is incomplete.
Explanations:- For sulfur trioxide, there are total 24 valence electrons. S is the central atom. Two O atoms are bonded to S via single bonds and the third O is bonded to S via double bond. So, in this way, the octet of each O is complete. Total 8 electrons are used in bonding. Each of the single bonded O has three lone pairs and the double bonded O has two lone pairs. It means total 16 electrons are present in the form of lone pairs. The sum of electrons used in bonding and present as lone pairs is 16+8 = 24 and this is exactly same as total valence electrons. So, the octet of S is also complete.
hydrogen sulfide has total 8 valence electrons. H has only one valence electron and can form only a single bond. So, two H atoms are bonded to S via single bonds. Total 4 electrons are used in bonding and remaining 4 electrons are present as two lone pairs on S. So, the octet of S is also complete.
Phosphane has total 8 valence electrons. P is the central atom and the three H atoms are bonded to it via single bonds. Total 6 electrons are used in bonding and rest of the two electrons are present as one lone pair on P. The octet of P is also complete.
NO has 11 valence electrons. Either we make a single, double or triple bond between N and O, the octet for at least one of them is incomplete as there are add number of electrons. The best lewis structure of NO has a triple bond between N and O, 4 electrons around it and N has 3 electrons around it. The octet of O is complete but the octet of N is incomplete as it could complete only 7 electrons.
So, the right answer is NO.
Lewis structures for all the four molecules are given below:
The answer is lower. when there’s a lower temperature the molecules will be moving at a lower speed. a lower speed means less thermal energy.
Hey there!
Molar mass NaCl = 58.44 g/mol
Number of moles
n = mass of solute / molar mass
n = 59.76 / 58.44
n = 1.0225 moles of NaCl
Volume in liters:
270 mL / 1000 => 0.27 L
Therefore:
M = number of moles / volume ( L )
M = 1.0225 / 0.27
= 3.78 M
Hope that helps!
For 1. 00 l of an aqueous buffer containing 60. 0 mmol of acetic acid (pa=4. 76) and 40. 0 mmol of acetate, the pH of this buffer is 4.58.
<h3>What is handerson Hasselbalch equation? </h3>
It is expressed as:
pH = pKa + log [A-]/[HA]
where,
[A-] is the molar concentration of conjugate base
[HA] is the molar concentration of weak acid
Given,
pKa = 4.76
<h3>Calculation of concentration:</h3>
C = n/V
= 60/1000
= 0.06M
C = 40/1000
= 0.04M
Now, substituting values in equation we get,
pH = 4.76 + log(0.04/0.06)
pH = 4.76 + (-0.176)
pH = 4.58
Thus by using Henderson Hasselbalch equation we find the value of pH of the buffer is 4.58.
learn more about pH :
brainly.com/question/9529394
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