Answer:
Explanation:
Assume 100% ionization:
1) 0.100 M solution K₂SO₄
This means, that you have to find which of the choices is a solution that contains the same 0.300 M ion concentration.
2) 0.0800 M Na₂CO₃
This is not equal to 0.300 M, so this solution would not contain the same total concentration as a 0.100 M solution of K₂SO₄, and is not the right answer.
3) 0.100 M NaCl
This is not equal to 0.300 M ion, so not a correct option.
4) 0.0750 M Na₃PO₄
Hence, this ion concentration is equal to the ion concentration of a 0.100 M solution of K₂SO₄, and is the correct choice.
5) 0.0500 M NaOH
Not equal to 0.300 M, so wrong choice.
B. Molecule
C. Matter
D. Compound
Molecule is a chemical substance that cannot be broken down into another chemical substance.
Answer:
The correct answer is A. An element.
Explanation:
An element is a chemical substance that cannot be broken down into another chemical substance.
+2
B.
-1
C.
+1
D.
-2
The electrical charge of the oxygen ion is -2.
Answer:
Se + 2e- => Se-2
Explanation:
Ions are electrically charged particles, formed due to the gain or loss of electrons by an atom.
There are two types of ions cations and anions. An element that loses their electrons and forms positive ions are cations while metals and element that gains one or more electrons and forms negative ions are anions.
Selenium is an atom with atomic number 34 and represented as Se. The electronic configuration of Se is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p4. Selenium will gain 2 more electrons to complete it p orbital and form an ion Se-2.
The equation is as below:
Se + 2e- => Se-2
2. A 33.2 L tank contains 280 g of compressed helium. If the pressure inside the tank is 700.0 kPa, what is the temperature of the compressed gas? You must convert the mass of helium into moles using the molar mass of He. The conversion factor will be 1 mol / molar mass of helium. R = 8.31 kPa x L / mol x K
Answer: See below
Explanation:
1. To calculate the mass, you know you can convert by using molar mass. Since mass is in grams, we can use molar mass to convert moles to grams. This calls for the Ideal Gas Law.
Ideal Gas Law: PV=nRT
We manipulate the equation so that we are solving for moles, then convert moles to grams.
n=PV/RT
P= 100 kPa
V= 0.831 L
R= 8.31 kPa*L/mol*K
T= 27°C+273= 300 K
Now that we have our values listed, we can plug in to find moles.
We use the molar mass of NO₂ to find grams.
The mass is 1.52 g.
2. To calculate the temperature, we need to use the Ideal Gas Law.
Ideal Gas Law: PV=nRT
We can manipulate the equation so that we are solving for temperature.
T=PV/nR
P= 700.0 kPa
V= 33.2 L
R= 8.31 kPa*L/mol*K
n= 70 mol
Now that we have our values, we can plug in and solve for temperature.
The temperature is 40 K.