<span>The density of an iceberg is less than that of water and that is why it floats. It is the same as ice cubes floating on water too. Water is a very unique substance in that it is one of few compounds where cooling it past freezing point decreases its density (study hydrogen bonds). The possible answers are therefore A or C. If the majority of the ice is below the water then it should be clear from common sense that A is the correct answer as it would mostly float on the top with just a little under the surface if the answer were as low as C. See Archimedes Principle for an explanation of how much of the ice floats and how much is underwater.</span>
Q1)
the number of moles can be calculated as follows
number of moles = mass present / molar mass
number of moles is the amount of substance.
4.8 g of Ca was added therefore mass present of Ca is 4.8 g
molar mass of Ca is 40 g/mol
molar mass is the mass of 1 mol of Ca
therefore if we substitute these values in the equation
number of moles of Ca = 4.8 g / 40 g/mol = 0.12 mol
0.12 mol of Ca is present
q2)
next we are asked to calculate the number of moles of water present
again we can use the same equation to find the number of moles of water
number of moles = mass present / molar mass
3.6 g of water is present
sum of the products of the molar masses of the individual elements by the number of atoms
H - 1 g/mol and O - 16 g/mol
molar mass of water = (1 g/mol x 2 ) + 16 g/mol = 18 g/mol
molar mass of H₂O is 18 g/mol
therefore number of moles of water = 3.6 g / 18 g/mol = 0.2 mol
0.2 mol of water is present
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:
C.) 0.7967
Explanation:
Hello,
Normal distribution is used here as:
In this case, the sample's pH is 8.47, the average pH 8.5, standard deviation 0.22 and sample size 37, thus:
Now, based on the table for standard normal distribution which comes from a symmetric bell-like graph, the probability is 0.797 which matched with the C answer.
Best regards.
