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3 years ago

How many grams of kno3 pellets must be dissolved in water in order to prepare 100 ml of a 8 m kno3?

1 answer:

Montano1993 [528]3 years ago

4 0

In 8M of KNO3, there are x moles of KNO3 divided by (100/1000)L of water (because molarity is concentration, given by no. of moles divided by total volume in liters).

by changing the subject of formula, x = 0.1L × 8M = 0.8mol

given the no. of mol of KNO3, mass of KNO3 is given by no. of mol multipled by the relative molecular mass of KNO3.

mass = 0.8mol × 101.10g/mol (or whatever your periodic table says) = 80.88g

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write a balanced chemical equation for each single replacement reaction that takes place in aqueous solution. write no reaction

Illusion [34]

The question is incomplete, here is the complete question:

Write a balanced chemical equation for each single replacement reaction that takes place in aqueous solution. write no reaction if a reaction does not occur

1.) Zn + PbCl₂

2.) Cu + Fe(NO₃)₂

Answer:

For 1: The reaction does occur.

For 2: The reaction does not occur.

Explanation:

Single displacement reaction is defined as the reaction in which more reactive element displaces a less reactive element.

The reactivity of metal is determined by a series known as reactivity series. The metals lying above in the series are more reactive than the metals which lie below in the series.

$A+BC\rightarrow AC+B$

For the given options:

For 1:

Zinc is more reactive than lead as it lies above in the series. So, it will displace lead from its chemical equation.

The chemical equation for the reaction of zinc and lead chloride follows:

$Zn+PbCl_2\rightarrow ZnCl_2+Pb$

For 2:

Copper is less reactive than iron as it lies below in the series. So, it will not displace iron from its chemical equation.

The chemical equation for the reaction of copper and iron (II) nitrate follows:

$Cu+Fe(NO_3)_2\rightarrow \text{No reaction}$

3 0

3 years ago

What is the density of a cube that has a mass of 25 g in a volume of 125 cm 3

GalinKa [24]

The density of an object is defined to be its mass divided by the volume it occupies. For this problem, the mass of the cube was given to be 25 g while its volume is 125 cm³. Thus, we simply divide 25 g by 125 cm³ to get the object’s density. We then calculate that the cube has a density of 0.2 g/ cm³.

3 0

3 years ago

A sample of gaseous methyl ether has a mass of 8.12g and occupies a volume of 3.96L at STP. What is the molecular weight of meth

Naya [18.7K]

Molar volume is when 1 mol of any gas occupies 22.4 L at STP.
Methyl ether has a mass of 8.12 g,
Volume occupied - 3.96 L
If 22.4 L occupied by 1 mol of gas
Then 3.96 L occupied by 1/22.4 x 3.96 = 0.176 mol of gas
The mass of 0.176 mol = 8.12 g
Molar mass is mass of 1 mol
Therefore mass of 1 mol = 8.12/0.176 = 46.1
Molecular weight is 46.1 g/mol

5 0

3 years ago

Read the following reactions.

garik1379 [7]

Answer:

Only Reaction 1

Explanation:

In reaction 1, there is a change in state from solid to liquid. Hence, there is an increase in number of ways particles and their energies could be arranged. As a result, entropy increases.

In reaction 2, there is a decrease in amount of gas particles (4 mol to 2 mol). Hence there is a decrease in the number of ways particles and their energies could be arranged. As a result entropy decreases

5 0

3 years ago

What is the range of accuracy for food temperature?.

telo118 [61]

Answer:

+ 2 degrees Fahrenheit

Explanation:

7 0

2 years ago