Answer:
737.52 mL de agua
Explanation:
En este caso solo debes usar la expresión de molaridad de una solución la cual es:
M = moles / V
Donde:
V: Volumen de solución.
Como queremos saber la cantidad de agua, queremos saber en otras palabras cual es la cantidad de solvente que se utilizó para preparar los 800 mL de disolución.
Una disolución se prepara con un soluto y solvente. El soluto lo tenemos, que es el nitrato de plata. Con la expresión de arriba, calculamos los moles de soluto, y luego su masa. Posteriormente, calculamos el volumen con la densidad, y finalmente podremos calcular el solvente de esta forma:
V ste = Vsol - Vsto
Primero calcularemos los moles de soluto:
moles = M * V
moles = 2 * 0.800 = 1.6 moles
Con estos moles, se calcula la masa usando el peso molecular reportado que es 169.87 g/mol:
m = moles * PM
m = 1.6 * 169.87 = 271.792 g
Ahora usando el valor de la densidad, calcularemos el volumen de soluto empleado:
d = m/V
V = m/d
V = 271.792 / 4.35
V = 62.48 mL
Finalmente, la cantidad de agua necesaria es:
V agua = 800 - 62.48
V agua = 737.52 mL
Answer:
N and P
Explanation:
Anion:
When an atom gain the electrons anion is formed. The negative sign shows that atom gain electron because number of electron are greater than protons or we can say that negative charge becomes greater than positive charge.
Cation:
When atom lose electron cation is formed. The atom thus have positive charge because number of positive charge i.e protons are increased are greater than negative charge or electron.
In given problem N and phosphorus both can gain three electrons which means negative charge becomes greater that's why the extra electron gained by atoms are written as -3 and both form anion with charge -3.
while Al form cation with charge +3 Mg form cation with charge +2 and iodine and bromine both form anion with charge of -1.
Answer:
Explanation:
Li(s)+1/2 F₂(g)→LiF(s)
In this reaction one mole of product is formed from gaseous state of reactants . So this reaction will represent the reaction for which ΔH∘rxn equals to ΔH∘f .
In other reaction one mole is not produced if we balance the reaction. The reactant must be in gaseous state . ΔH∘f . represents heat of formation . ΔH∘rxn represents heat of reaction .
Answer:
You can increase your precision in the lab by paying close attention to detail, using equipment properly and increasing your sample size. Ensure that your equipment is properly calibrated, functioning, clean and ready to use.
