1) For example, sodium oxide (Na₂O).
One one molecule of sodium oxide has one sodium atome (Na) and two oxygen atoms (O).
The subscript after element shows the number of elements in a molecule.
2) Yes, it possible for two different compounds to be made from the exact same two elements.
This are isomers, same molecular formula, but different arrangements of atoms.
For example, n-butane (C₄H₁₀) and 2-methylpropane (C₄H₁₀).
3) There are large number of compounds in this world, around 40 millions.
The added KI does not have any impact
The reaction invovles Titration of vitaminc ( Ascorbic acid)
ascorbic acid + I₂ → 2 I⁻ + dehydroascorbic acid
the excess iodine is free reacts with the starch indicator, forming the blue-black starch-iodine complex.
This is the endpoint of the titration. since alreay excess KI is added ( the source of Iodine), it does not have an influence.
Answer B
Hope this helps!
Answer:
Explanation:
1. To identify what's been oxidised and what's been reduced in a redox reaction
2. In naming compounds
3. To work out reacting proportions in titration reactions
Answer:
Explanation:
Hola!
En este caso, consideramos que la disociación de ácido acético ocurre:
Así, mediante la solución del equilibrio ácido, podemos calcular la concentración de iones hidronio que posteriormente sirven para calcular el pH de la solución, por tal razón, debemos calcular el equilibrio dada la constante de equilibrio y por medio de la ley de acción de masas en términos del cambio 
como cualquier problema de equilibrio:
![Ke=\frac{CH_3COO^-][H^+]}{[CH_3COOH]}\\\\1.76x10^{-5}=\frac{x*x}{1x10^{-14}M-x}](https://tex.z-dn.net/?f=Ke%3D%5Cfrac%7BCH_3COO%5E-%5D%5BH%5E%2B%5D%7D%7B%5BCH_3COOH%5D%7D%5C%5C%5C%5C1.76x10%5E%7B-5%7D%3D%5Cfrac%7Bx%2Ax%7D%7B1x10%5E%7B-14%7DM-x%7D)
Resolviendo para , tenemos 
Así, la concentración de hidrógeno es igual a x, por lo que el pH:
![pH=-log([H^+])=-log(0.999x10^{-14})\\\\pH=14](https://tex.z-dn.net/?f=pH%3D-log%28%5BH%5E%2B%5D%29%3D-log%280.999x10%5E%7B-14%7D%29%5C%5C%5C%5CpH%3D14)
Dicho valor tiene sentido desde que la concentración de hidrógeno es casi despreciable, por lo que se puede asumir que tiende a ser básica.
Saludos!
