Answer:
The van't hoff factor of 0.500m K₂SO₄ will be highest.
Explanation:
Van't Hoff factor was introduced for better understanding of colligative property of a solution.
By definition it is the ratio of actual number of particles or ions or associated molecules formed when a solute is dissolved to the number of particles expected from the mass dissolved.
a) For NaCl the van't Hoff factor is 2
b) For K₂SO₄ the van't Hoff factor is 3 [it will dissociate to give three ions one sulfate ion and two potassium ions]
Out of 0.500m and 0.050m K₂SO₄, the van't hoff factor of 0.500m K₂SO₄ will be more.
c) The van't Hoff factor for glucose is one as it is a non electrolyte and will not dissociate.
Answer:
-177.9 kJ.
Explanation:
Use Hess's law. Ca(s) + CO2(g) + 1/2O2(g) → CaCO3(s) ΔH = -812.8 kJ 2Ca(s) + O2(g) → 2CaO(s) ΔH = -1269.8 kJ We need to get rid of the Ca and O2 in the equations, so we need to change the equations so that they're on both sides so they "cancel" out, similar to a system of equations. I changed the second equation. Ca(s) + CO2(g) + 1/2O2(g) → CaCO3(s) ΔH = -812.8 kJ 2CaO(s) → 2Ca(s) + O2(g) ΔH = +1269.8 kJ The sign changes in the second equation above since the reaction changed direction. Next, we need to multiply the first equation by two in order to get the coefficients of the Ca and O2 to match those in the second equation. We also multiply the enthalpy of the first equation by 2. 2Ca(s) + 2CO2(g) + O2(g) → 2CaCO3(s) ΔH = -1625.6 kJ 2CaO(s) → 2Ca(s) + O2(g) ΔH = +1269.8 kJ Now we add the two equations. The O2 and 2Ca "cancel" since they're on opposite sides of the arrow. Think of it more mathematically. We add the two enthalpies and get 2CaO(s) + 2CO2(g) → 2CaCO3(s) and ΔH = -355.8 kJ. Finally divide by two to get the given equation: CaO(s) + CO2(g) → CaCO3(s) and ΔH = -177.9 kJ.
Lets take a moment to list all the characteristics of the group 18 (also known as noble gases and/or group 8) elements:
- They have 8 valence electrons.
- Don't need ANY more electrons because their octet is full (stable).
- Are stable
- Not reactive
- Known as the noble gases
Now.. lets take some time to think about why elements want to form ions:
Elements form ions to either gain or lose valence electrons to the element they bond with. This helps them GAIN a full octet. What is a full octet, you may ask? An octet is when an element has all 8 valence electrons and is stable, making it nonreactive.
Why would an element with a full octet want to bond? It already has a full octet, it does not need to bond.
That, my fellow Brainly user, is why the noble gases do not need to bond.
I really do hope this helps! Enjoy, and good luck on the studies.
If he was 30.8% too low, it means that he was at 69.2% of the boiling point needed. So 50o C is 69.2% of total.
In order to know what 100% is, you can divide the number by it's percentage and then multiply it by a hundred.
So: 50/30.8=1.623
1.623*100=162.3
So the correct boiling point of the liquid he was working with in the lab is 162.3 oC
Answer:
Look below
Explanation:
The formula for density is:
Therefore in order to find the density of a solid, you must find the mass and the volume first.
To find the mass, you can use a scale.
To find the volume, you can use the water displacement method. For example, if you fill the water of a graduated cylinder to 10 mL, and then you put a rock inside, and it rises to 15 mL, then the volume (of the rock) is 15mL-10mL=5mL.
