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Lady bird [3.3K]
3 years ago
5

Which is a sign of a chemical change?

Chemistry
1 answer:
Igoryamba3 years ago
7 0
The correct answer for the question it is option  

>>>>D<<<<

%100 sure 

if you need another answer welcome to come

You might be interested in
Calculate the ph of a 0.60 m h2so3, solution that has the stepwise dissociation constants ka1 = 1.5 × 10-2 and 1.82 1.06 1.02 2.
Vsevolod [243]
Missing in your question Ka2 =6.3x10^-8
From this reaction:
 H2SO3 + H2O ↔ H3O+  + HSO3-
by using the ICE table :
                H2SO3     ↔    H3O     +    HSO3- 
intial         0.6                     0                  0
change     -X                      +X                +X
Equ         (0.6-X)                  X                   X

when Ka1 = [H3O+][HSO3-]/[H2SO3]
So by substitution:
1.5X10^-2 = (X*X) / (0.6-X) by solving this equation for X
∴ X = 0.088
∴[H2SO3] = 0.6 - 0.088 = 0.512
[HSO3-] = [H3O+] = 0.088

by using the ICE table 2:
                 HSO3-     ↔   H3O     +     SO3-
initial        0.088              0.088              0
change    -X                      +X                   +X
Equ         (0.088-X)          (0.088+X)          X

Ka2= [H3O+] [SO3-] / [HSO3-]
we can assume [HSO3-] =  0.088 as the value of Ka2 is very small
 6.3x10^-8 = (0.088+X)*X / 0.088
X^2 +0.088 X - 5.5x10^-9= 0 by solving this equation for X
∴X= 6.3x10^-8
∴[H3O+] = 0.088 + 6.3x10^-8
               = 0.088 m ( because X is so small)
∴PH= -㏒[H3O+]
       = -㏒ 0.088 = 1.06 
5 0
3 years ago
Read 2 more answers
I don't know how to do this, pls help!
Aliun [14]
Cations from smallest to largest
Li⁺ ,Na⁺, K⁺ (from Periodic Table, the bigger number of period, the bigger size, of atom, so the bigger size of cation)

1) LiF smaller  cation then KF
1,036                                 <span>853
</span><span>The lattice energy increases as cations get smaller, as shown by LiF and KF.
</span><span>I think this one should be correct answer, because the compared substances have also the same anion, and we can compare cations in them.

2) The same cation Li , so wrong statement.

3)</span>The same cation Na , so wrong statement.

4) NaCl smaller cation then KF
  786                                   853
7 0
3 years ago
Read 2 more answers
What is the volume if 1.5 mol of gas has a pressure of 700 torr at 15°C?
Tasya [4]

Answer:

V = 38.48 L

Explanation:

Given that,

No. of moles = 1.5 mol

Pressure, P = 700 torr

Temperature, T = 15°C = 288 K

We need to find the volume of the gas. The ideal gas equation is given by :

PV=nRT\\\\V=\dfrac{nRT}{P}\\\\V=\dfrac{1.5\times 62.36\times 288}{700}\\\\V=38.48\ L, R = L.Torr.K⁻¹.mol⁻¹

So, the required volume is equal to 38.48 L.

7 0
3 years ago
What is the pH of a substance with a hydrogen concentration of 1.0 x 10-13?
Nikolay [14]

Answer:

Favorite Answer

1.0 x10^-14 = (1.0 x 10^-13) (x)

x = 1.0 x 10^-1 = 0.1 M (this is the [OH-])

pOH = -log 0.1 = 1.0

Explanation:

I hope this helps :) sorry if not :(

4 0
3 years ago
A 10 gram sample of iron reacts with oxygen to form 18.2 grams of ferric oxide. How many grams of oxygen reacted?
RoseWind [281]

Answer:

\boxed {\boxed {\sf 8.2 \ grams}}

Explanation:

According to the Law of Conservation of Mass, the mass of the products must equal the mass of the reactants.

  • mass products = mass reactants

In this problem, the reaction is:

iron + oxygen = ferric \ oxygen

  • The reactants are iron and oxygen. We know the mass of the iron sample is 10 grams.
  • The product is ferric oxide. The mass of the ferric oxide sample is 18.2 grams.

10 \ g + oxygen=18.2 \ g

We want to find how many grams of oxygen reacted. We have to get the oxygen by itself. 10 is being added to oxygen. The inverse of addition is subtraction. Subtract 10 from both sides of the equation.

10 \ g - 10 \ g+ oxygen = 18.2 \ g - 10 \ g

oxygen= 18.2 \ g - 10 \ g

oxygen= 8.2 \ g \\

<u>8.2 grams of oxygen </u>reacted with 10 grams of iron to form 18.2 grams of ferric oxide.

8 0
3 years ago
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