What change takes place when a liquid absorbs heat energy without increasing its temperature?

There are two naturally occurring isotopes of bromine. 79Br has a mass of 78.9183 amu. 81Br has a mass of 80.9163 amu. Determine

Ede4ka [16]

Atomic mass of Br = 79.904
Now lets say y% is abundance of 79Br. 
Then abundance of 81Br = (100 - y) 
mass due to 79Br = 78.9183 * y/100 = 0.789183y
mass due to 81Br = 80.9163 x (100 - y)/100 = 0.809163(100 - y) 
Therfore
0.789183y+ 0.809163(100 - y) = 79.904 
0.789183y + 80.9163 - 0.809163y = 79.904 
 - 0.01998y= 79.904 - 80.9163
= - 1.0123 
y = 1.0123/0.01998 = 50.67% 
 79Br = 50.67% 
now
81Br = 100 - 50.67 = 49.33%
hope this helps

4 0

4 years ago

6 Calculate the number of molecules in 8 g of oxygen.

Mariana [72]

Answer:

If you mean the number of atoms in 8g of oxygen, it's 3.011 x 10^23 atoms.

Explanation:

Convert the grams to moles. 8 grams of oxygen is 0.5 moles. Then multiply the number of moles by Avogadro's number: 6.022 x 10^23.

3 0

3 years ago

The following anions can be separated by precipitation as silver salts: Cl- , Br- , I- , CrO4 2-. If Ag is added to a solution c

dalvyx [7]

Answer:

AgI, AgBr, AgCl and Ag₂CrO₄

Explanation:

Ksp (product solubility constant) is defined as the equilibrium constant of the general reaction:

XₐYₙ(s) → aXⁿ⁺(aq) + nYᵃ⁻(aq)

Where X is cation and Y is anion.

Ksp = [aXⁿ⁺]ᵃ [nYᵃ⁻]ⁿ

The presence of XₐYₙ(s) produce ax moles of aXⁿ⁺ and nx moles of Yᵃ⁻. Where X is the solubility of the compound.

Replacing in Ksp:

Ksp = [ax]ᵃ [nx]ⁿ

Solving for x, Solubility (S) is defined as:

$S = \sqrt[n+a]{\frac{Ksp}{a^{a} n^n} }$

For AgCl, Ag₂CrO₄, AgBr and AgI solubilities are:

$S = \sqrt[2]{\frac{1.8x10^{-10}}{1} }$ = 1.34x10⁻⁵M

$S = \sqrt[3]{\frac{1.1x10^{-12}}{4} }$ = 6.50x10⁻⁵M

$S = \sqrt[2]{\frac{5.4x10^{-13}}{1} }$ = 7.35x10⁻⁷M

$S = \sqrt[2]{\frac{8.5^{-17}}{1} }$ = 9.22x10⁻⁹M

The lower solubility is the first compound in precipitate, thus, order of precipitation is:

AgI, AgBr, AgCl and Ag₂CrO₄

8 0

3 years ago

Please help! I'd appreciate it.

jonny [76]

I believe your answer is the second option.

7 0

3 years ago

Read 2 more answers

The reaction system: POCl3(g) POCl(g) + Cl2(g) is at equilibrium. Which of the following statements describes the behavior of th

mars1129 [50]

Answer: (B) The reverse reaction will proceed to establish equilibrium.

Explanation:

Any change in the equilibrium is studied on the basis of Le-Chatelier's principle.

This principle states that if there is any change in the variables of the reaction, the equilibrium will shift in the direction to minimize the effect.

For the given equation:

$POCl_3(g)\leftrightharpoons POCl(g)+Cl_2(g)$

Given : when $POCl$ is added to the system

If the concentration of $POCl$ that is the product is increased, so according to the Le-Chatlier's principle, the equilibrium will shift in the direction where decrease of concentration of $POCl$ takes place. Therefore, the equilibrium will shift in the left or backward direction.

Thus the reaction will shift towards reactants to reestablish equilibrium and thus partial pressure of $POCl$ and $Cl_2(g)$ decreases and the partial pressure of $POCl_3$ increases.

8 0

3 years ago