Kf = 1.86
Number of moles :
Molar mass <span> ethylene glycol = 62.0 g/mol
40.0 / 62.0 => 0.645 moles
Molality :
mass of solvent = 60.0 / 1000 => 0.06 kg
m = moles / kg solvent
m = </span><span>0.645 / 0.06
= 10.75 m
</span>Δt = Kf x molality
Δt = (- 1.86) x 10.75 => - 20.1ºC
<span>
Answer A
hope this helps!</span>
Answer:
T₁ = 39 K
Explanation:
Given data:
Initial pressure = 1023.6 kpa
Final pressure = 8114 kpa
Final temperature = 36°C (36+ 273= 309K)
Initial temperature = ?
Solution:
P₁/T₁ = P₂/T₂
T₁ = P₁×T₂ /P₂
T₁ = 1023.6 kpa × 309 K /8114 kpa
T₁ = 316292.4 K. Kpa /8114 kpa
T₁ = 39 K
Thus original pressure was 39 k.
Answer:
1. The Dean's theory is an untested idea that he will investigate; scientific theories have already been investigated.
Explanation:
Scientific theory by definition is something that can be tested. However, in science, a scientific theory generally is something that has already been tested (hence the scientific definition). Remember from math, Theorem is something that can be tested, Postulate is something you can't. By prescribing theorem on it, it means that you can test whether it is true or not.
As for the Dean, he has a "theory" of why phones are being stolen from student backpacks. However, it seems that he did not test for it (i.e., install security cameras, etc.). This means that, without testing, he cannot say it is a scientific theory.
Answer:
Potassium (K) and Fluorine (F)
Explanation:
A salt is formed with a metal and non-metal element from the periodic table of elements. if you look at the online ptable.com the upper right hand corner of each element shows the valence electrons for each element, and how many are in each shell for that element. Fluorine (F) has 7 valence electrons in its outer most shell, which means there is room for 1 more electron since the second shell can hold a max of 8. Potassium(K) has 1 electron in its outer most shell- which means is can fill in the 1 space available that fluorine has in its outer most shell. Since Potassium(K) is a metal and Fluorine(F) is a non-metal they can form an ionic compound, salt.
The concentration of AlCl3 solution if 150 ml of the solution contains 550 mg of cl- ion is 0.0344 M
calculation
concentration = moles /volume in liters
volume in liters = 150 /1000= 0.15 L
number of moles calculation
write the equation for dissociation of Al2Cl3
that is AlCl3 ⇔ Al^3+ + 3 Cl ^-
find the moles of Cl^- formed
moles =mass/molar mass
mass in grams= 550/ 1000 =0.55 grams
molar mass of Cl^- =35.5 g/mol
moles is therefore= 0.55/35.5 =0.0155 moles
by use of mole ration betweem AlCl3 to Cl^- which is 1:3 the moles of AlCl3 is =0.0155 x 1/3= 5.167 x10^-3 moles
concentration of AlCl3 is therefore= 5.167 x10^-3/ 0.15 =0.0344 M