Answer:
Presence of impurities in the product.
Explanation:
Laboratory experience has shown that the percent yield obtained from a reaction may be greater than 100% if the product obtained from the reaction contains impurities that causes its mass to be greater than it actually would be if the product was pure.
A typical impurity that may be present in a product is the solvent used. This can be removed by evaporation of the solvent or by washing the product thoroughly.
Reaction of solid products with gases may also increase the percentage yield above 100%.
Answer:- A. 
and 
Explanations:- In general, 
In acid-base reaction the acid gives hydrogen ion and the base gives hydroxide ion and these ions combine to form water. Rest of the ions from acid and base combine to form the salt.
Nitric acid breaks to give hydrogen ion and nitrate ion. Similarly, NaOH breaks to give sodium ion and hydroxide ion. Since, hydrogen ion and hydroxide ions form water, the sodium ion and nitrate ion forms the salt, sodium nitrate.
The reaction is shown as:
So, the right choice is A.
Answer:
9.03×10²³ molecules of H₂O
Explanation:
To solve this, we need to propose the reaction
NH₄ClO₄ → ammonium perchlorate
Al → Aluminum
Those are the reactants; the reaction is:
6NH₄ClO₄ + 10Al → 5Al₂O₃ + 3N₂ + 6HCl + 9H₂O
Then, water is one of the products. If we see the reaction, is a redox type.
Ratio is 6:9. In conclussion:
6 moles of ammonium perchlorate can produce 9 moles of H₂O
Then 1 mol of salt, may produce (1 . 9)/6 = 1.5 moles of water
Let's count the molecules:
1.5 mol . 6.02×10²³ molecules /mol = 9.03×10²³ molecules of H₂O
Answer:
0.020g de sulfato de plomo se requieren
La concentración de la solución diluida es de 3ppm
Explanation:
Las partes por millón (ppm) son definidas como:
miligramos soluto / 1L solución.
Si deseas preparar una solución a 100ppm de sulfato de plomo (II) necesitas 100mg de este sulfato en 1L. En 200mL = 0.200L vas a necesitar:
0.200L × (100mg / 1L) = 20mg de sulfato de plomo (II).
Como 1000mg = 1g,
20mg × (1g / 1000mg) = 0.020g de sulfato de plomo se requieren.
Ahora, se van a tomar 30mL de esta solución y se diluirán a 1000mL. Se diluye la solución:
1000mL / 30mL = 33.33 veces.
Como la solución inicial es de 100ppm, esta dilución genera una solución de concentración:
100ppm / 33.33 = 3ppm
Answer:
Sucrose 342.34
Mysristic acid 228.42
Explanation:
The first step is to write out the formula of the substance in question. Let us start with sucrose. 
. Then use that to help you determine the molecular weights using the relative atomic mass of each species.
molecular weight = (12.01*12) + (1.01*22) + (16.00*11) = 342.34
Be sure to write no units for this answer. This is not the molar mass, this is the relative molecular mass. It's on a relative scale not in grams
We repeat the steps above for mysristic acid, formula 
.
molecular weight = (12.01*14) + (1.01*28) + (16*11) = 228.42
