Answer:
There are five signs of a chemical change:
Colour Change.
Production of an odour.
Change of Temperature.
Evolution of a gas (formation of bubbles)
Precipitate (formation of a solid).
Answer:
0.095 moles of O₂ are left over.
Explanation:
First of all, state the balanced reaction:
2NO + O₂ → 2NO₂
We determine moles of each reactant:
20.2 g . 1mol / 30g = 0.673 moles of NO
13.8g . 1mol / 32g = 0.431 moles of oxygen
Oxygen is the excess reactant. Let's see.
For 2 moles of NO I need 1 mol of O₂
Then, for 0.673 moles of NO I may use (0.673 .1) /2 = 0.336 moles
I have 0.431 moles of O₂ and I only need 0.336 mol. According to reaction, stoichiometry is 2:1.
In conclussion, the moles of excess reactant that will be left over:
0.431 - 0.336 = 0.095 moles
Answer:
A
Explanation:
I think this is true letter a
Answer:
1.427x10^-3mol per L
Explanation:

I could use ⇌ in the math editor so I used ----
from the question each mole of Y(IO3)3 is dissolved and this is giving us a mole of Y3+ and a mole of IO3^3-
Ksp = [Y^3+][IO3-]^3
So that,
1.12x10^-10 = [S][3S]^3
such that
1.12x10^-10 = 27S^4
the value of s is 0.001427mol per L
= 1.427x10^-3mol per L
so in conclusion
the molar solubility is therefore 1.427x10^-3mol per L
Hello!
The reaction between HBr and KOH is the following:
HBr+KOH
→H₂O + KBr
To calculate the amount of HBr left after addition of KOH, you'll use the following equations:
![HBr_f=HBr_i-KOH=([HBr]*vHBr)-([KOH]*vKOH) \\ \\ HBr_f=(0,25M*0,64L)-(0,5M*0,32L)=0 mol HBr](https://tex.z-dn.net/?f=HBr_f%3DHBr_i-KOH%3D%28%5BHBr%5D%2AvHBr%29-%28%5BKOH%5D%2AvKOH%29%20%5C%5C%20%20%5C%5C%20HBr_f%3D%280%2C25M%2A0%2C64L%29-%280%2C5M%2A0%2C32L%29%3D0%20mol%20HBr)
That means that after the addition of 32 mL of KOH, there is no HBr left in the solution and the pH should be
neutral, close to 7.
Have a nice day!