A3B9 represents a molecular formula. The representation of the empirical formula for this compound is AB3. This is so because the empirical formula is the simplest ratio of the atoms present in the molecule. You get AB3 when you divide the subscripts of A3B9, this is 3 and 9, by the greatest common factor, which is 3. 3/3 = 1 and 9/3 = 3, so the subscripts for the empirical formula are 1 and 3, which is what AB3 represents. <span>Answer: AB3.</span>
Answer:
0.26×10²³ molecules
Explanation:
Given data:
Volume of gas = 1.264 L
Temperature = 168°C
Pressure = 946.6 torr
Number of molecules of gas = ?
Solution:
Temperature = 168°C (168+273= 441 K)
Pressure = 946.6 torr (946.6/760 = 1.25 atm)
Now we will determine the number of moles.
PV = nRT
P= Pressure
V = volume
n = number of moles
R = general gas constant = 0.0821 atm.L/ mol.K
T = temperature in kelvin
n = PV/RT
n = 1.25 atm ×1.264 L / 0.0821 atm.L/ mol.K ×441 K
n = 1.58 /36.21 /mol
n = 0.044 mol
Now we will calculate the number of molecules by using Avogadro number.
1 mol = 6.022×10²³ molecules
0.044 mol × 6.022×10²³ molecules/ 1mol
0.26×10²³ molecules
Explanation:
Since HF is a weak acid, the use of an ICE table is required to find the pH. The question gives us the concentration of the HF.
HF+H2O⇌H3O++F−HF+H2O⇌H3O++F−
Initial0.3 M-0 M0 MChange- X-+ X+XEquilibrium0.3 - X-X MX M
Writing the information from the ICE Table in Equation form yields
6.6×10−4=x20.3−x6.6×10−4=x20.3−x
Manipulating the equation to get everything on one side yields
0=x2+6.6×10−4x−1.98×10−40=x2+6.6×10−4x−1.98×10−4
Now this information is plugged into the quadratic formula to give
x=−6.6×10−4±(6.6×10−4)2−4(1)(−1.98×10−4)−−−−−−−−−−−−−−−−−−−−−−−−−−−−√2x=−6.6×10−4±(6.6×10−4)2−4(1)(−1.98×10−4)2
The quadratic formula yields that x=0.013745 and x=-0.014405
However we can rule out x=-0.014405 because there cannot be negative concentrations. Therefore to get the pH we plug the concentration of H3O+ into the equation pH=-log(0.013745) and get pH=1.86
Here I found some info at Yahoo answers: https://answers.yahoo.com/question/index?qid=20090119191941AAB7oAb
The more electronegative an atom is the more unwilling it is to lose its electrons in a compound. If you do try to take a very EN atom away from a compound you'll need to apply a lot of energy for that to happen. I can give an example of a single atom though
<span>Cl has 7 valence electron filled and every atom wants to be like nobles (noble gases), so it's not going to give an electron away b/c it's really close to being like a noble gas. Noble gases are the most stable atoms, which is why I say stability counts.</span>
Answer:
They have properties of both metals and nonmetals
Explanation:
- Elements in the periodic table may be divided into Metals, non-metals, and metalloids.
- Metals are the elements that react by losing electrons to form stable positively charged ions known as cations. Examples are group 1, 2, and 3 elements together with transition elements.
- Non-metals are those elements that react by gaining electrons to form stable negatively charged ions called anions. Examples include oxygen, carbon, sulfur, etc.
- Metalloids, on the other hand, are elements that have both metallic and non-metallic properties.
- Metalloids occur between metals and non-metals in the periodic table. Examples include Boron and silicon among others.
