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4 days ago

What is the molarity of a solution of 14.0 g NH4Br in enough H2O to make 150 mL of solution?

2 answers:

8 0

To determine the molarity of a solution, you take the amount of solute in moles and divide it by the solution's volume. For NH4Br, its molar mass is known to be 98. Consequently, the molarity can be calculated as follows: (14/98) mol / 0.15 L = 0.95 mol/L.

KiRa [971]4 days ago

4 0

Explanation:

The concept of molarity is defined as the moles of solute per liter of solution.

In mathematical terms, Molarity = $\frac{no. of moles}{volume of solution in liter}$

Given that the solution's mass is 14.0 g with a volume of 150 mL or 0.15 L.

The number of moles is computed as $\frac{mass}{molar mass}$

The molar mass of $NH_{4}Br$ equals 97.94 g/mol.

This leads to the calculation of the number of moles = $\frac{14.0 g}{97.94 g/mol}$

= 0.142 mol

This allows the molarity to be calculated as follows.

Molarity = $\frac{no. of moles}{volume of solution in liter}$

= $\frac{0.142 mole}{0.15 L}$

= 0.946 mol/L

Thus, we can arrive at the conclusion that the molarity of this solution is 0.946 mol/L.

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Convert 3.8 Km/sec to miles/year

castortr0y [923]

To convert the speed from kilometers per second to miles per year, we'll utilize a conversion factor that relates these units. This involves either multiplying or dividing the original value based on the desired outcome. From general knowledge, we find that 1 mile equates to 1609 meters, while 1000 meters make up 1 kilometer. Moreover, there are 3600 seconds in an hour, 24 hours in a day, and 365 days in a year. The conversion process is as follows:

3.8 km/s ( 1000 m / 1 km ) ( 1 mile / 1609 meters ) ( 3600 s / 1 hr ) ( 24 hr / 1 day ) ( 365 days / 1 year ) = 74479055.3 miles per year

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11 days ago

How many known elements have atoms, in their ground-state, with valence electrons whose quantum numbers are n = 5 and l = 1?a. 3

Tems11 [846]

Answer:

c. 6.

Explanation:

Based on the question's description, the elements must be from the p-block of the periodic table and in the fifth period. They should have valence electrons located in the 5p orbital.

The following elements from the p-block of period 5 meet these criteria: Sr, In, Sn, Sb, Te, and I.

Therefore, there are a total of six such elements.

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23 hours ago

Which of the following could be considered a scientific statement?

Anarel [852]

Answer: D) X-rays exhibit lower frequency than microwaves

Explanation:

A scientific statement is one that relies on evidence gathered from experiments and direct observation of the natural world. Such a statement can be corroborated through appropriate experimental methods.

The option D illustrates a scientific statement because it allows for the frequency of both microwaves and X-rays to be assessed and contrasted. This process entails experimental and observational techniques, which validates it as a scientific statement.

6 0

2 days ago

Read 2 more answers

The ionic radius of a sodium ion is 2.27 angstroms (A) . What is this length in um

lions [985]

$\boxed{\sf 1Å=10^{-10}m}$

$\\ \rm\longmapsto 2.27Å$

$\\ \rm\longmapsto 2.27\times 10^{-10}m$

$\\ \rm\longmapsto 0.227\times 10^{-9}m$

$\\ \rm\longmapsto 0.0227\times 10^{-8}m$

$\\ \rm\longmapsto 0.00227\times 10^{-7}m$

$\\ \rm\longmapsto 0.00023\times 10^{-6}m$

$\\ \rm\longmapsto 0.00023\mu m$

6 0

12 days ago

Valproic acid, used to treat seizures and bipolar disorder, is composed of C, H, and O. A 0.165-g sample is combusted to produce

VMariaS [1037]

Answer:

The empirical formula is = $C_4H_8O$

The Valproic acid formula is = $C_8H_{16}O_2$

Explanation:

Mass of the produced water = 0.166 g

Molar mass of water = 18 g/mol

The moles of $H_2O$ are calculated as 0.166 g /18 g/mol = 0.00922 moles.

In 1 mole of water, there are 2 moles of hydrogen atoms.

Thus,

Moles of H = 2 x 0.00922 = 0.01844 moles

Each hydrogen atom's molar mass is 1.008 g/mol.

Hydrogen mass in the molecule = 0.01844 x 1.008 = 0.018588 g

Mass of produced carbon dioxide = 0.403 g

Molar mass of carbon dioxide = 44.01 g/mol

The moles of $CO_2$ are calculated as 0.403 g /44.01 g/mol = 0.009157 moles.

Each carbon atom's presence is 1 mole in 1 mole of carbon dioxide.

So,

Moles of C = 0.009157 moles

The molar mass of carbon is 12.0107 g/mol.

Carbon mass in molecule = 0.009157 x 12.0107 = 0.11 g

Since Valproic acid comprises only hydrogen, oxygen, and carbon, the oxygen mass in the sample = Total mass - Carbon mass - Hydrogen mass.

The sample's overall mass = 0.165 g.

Oxygen mass in the sample = 0.165 - 0.11 - 0.018588 = 0.036412 g

The molar mass of oxygen is 15.999 g/mol.

Moles of O = 0.036412 / 15.999 = 0.002276 moles

Taking the simplest ratio for H, O, and C yields:

0.01844: 0.002276: 0.009157

= 8: 1: 4

The empirical formula becomes $C_4H_8O$

While molecular formulas detail the precise count of atoms for each element, empirical formulas represent the simplest form or reduced ratio of these elements in the compound.

Consequently,

The molecular mass equals n × Empirical mass.

Here, n is a positive integer from 1, 2, 3...

Empirical mass = 4×12 + 8×1 + 16 = 72 g/mol.

Molar mass = 144 g/mol.

Thus,

The molecular mass = n × Empirical mass.

144 = n × 72

⇒ n = 2

The Valproic acid formula is = $C_8H_{16}O_2$

7 0

7 days ago