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3 years ago

Round to 4 significant figures: 42,561

Chemistry

1 answer:

arsen [322]3 years ago

7 0

6 is the fourth significant figures

if the number behind it is 5 or more then 5, you must add 1 to the number and ALL the number behind it will turn into 0

so that the answer is 42560

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What is the pressure of 1.50 moles of a gas in a 30.0L tank at a temperature of 285K?

julia-pushkina [17]

The pressure of the gas : 1.1685 atm

<h3>Further explanation</h3>

In general, the gas equation can be written

$\large {\boxed {\bold {PV = nRT}}}$

where

P = pressure, atm

V = volume, liter

n = number of moles

R = gas constant = 0.08206 L.atm / mol K

T = temperature, Kelvin

n=moles=1.5

V=volumes = 30 L

T=temperature=285 K

The pressure :

$\tt P=\dfrac{nRT}{V}\\\\n=\dfrac{1.5\times 0.082\times 285}{30}\\\\P=1.1685~atm$

7 0

3 years ago

Write the chemical equation for the dissolution reaction of solid iron(iii) hydroxide in water. include the phases of all specie

Allushta [10]

When solid iron (iii) hydroxide is dissolved into water, it ionizes or it dissociates into ions. These ions are the iron (iii) ions and the hydroxide ions. Iron(III) oxide is classified as a base when in aqueous solution since it produces hydroxide ions. It is a weak base so it does not completely dissociate into the solution. The dissociation equation would be:

Fe(OH)3 <-----> Fe3+ + OH-

To write a complete reaction, the reaction should be balanced wherein the number of atoms of each element in the reactant side and the product side should be equal. Also, the phases of the substances should be written. We do as follows:


Fe(OH)3 (s) <-----> Fe3+ (aq) + 3OH- (aq)

4 0

3 years ago

Suppose you have 81.8 g of Cd. How many Cd atoms are present? Report your answer in scientific notation using the format of 6.02

Lostsunrise [7]

Answer:

1. number of Cd atoms = 4.384 × 10²³

2. number of moles of Ti = 0.817 mol

3. molar mass of C₇H₆O₃ = 138.077 g/mol

4. moles of Sildenafil = 0.249 mmol

Explanation:

1. given data

mass of Cd = 81.8 g

number of Cd atoms = ?

molar mass of Cd = 112.411 g/mol

Solution

1st we find out the number of moles of Cd

number of moles = mass / molar mass

number of moles of Cd = 81.8 g / 112.411 g.mol⁻

number of moles of Cd = 0.728 mol

Now we find out the number of Cd atoms

number of atoms = moles × 6.022 × 10²³

number of Cd atoms = 0.728 (6.022 × 10²³)

number of Cd atoms = 4.384 × 10²³

2. Given data

Mass of Ti = 39.1 g

moles = ?

molar mass Ti = 47.867 g/mol

Solution

Now we will find out the number of moles

number of moles = mass / molar mass

number of moles of Ti = 39.1 g / 47.867 g.mol⁻

number of moles of Ti = 0.817 mol

3. Given data

chemical formula of Salicylic acid = C₇H₆O₃

molar mass of salicylic acid = ?

molar mass of carbon = 12.011

molar mass of hydrogen = 1.008

molar mass of oxygen = 15.999

molar mass of molecule = number of moles of atoms × molar mass of atoms

molar mass of C₇H₆O₃ = 7 (12.011) + 6 (1) + 3 (16)

molar mass of C₇H₆O₃ = 84.077 g + 6 g + 48 g

molar mass of C₇H₆O₃ = 138.077 g/mol

4. Given data

molar mass of Sildenafil = 474.5828 g/mol

mass given = 0.118 g

moles of Sildenafil = ?

Solution

Now we find out the number of moles

number of moles = mass / molar mass

number of moles Sildenafil = 0.118 g / 474.5828 g/mol

number of moles Sildenafil = 0.0003 mol

as this is very small amount we convert it into millimoles

millimoles = moles × 1000

millimoles of Sildenafil = 0.000249 × 1000

millimoles of Sildenafil = 0.249 mmol

4 0

3 years ago

Nitrogen us a component of all

Ede4ka [16]

Answer:

amino acids and urea

Explanation:

Amino acids are the building blocks of all proteins. Proteins comprise not only structural components such as muscle, tissue and organs, but also enzymes and hormones essential for the functioning of all living things. Urea is a byproduct of protein digestion.

4 0

3 years ago

Coefficient in a sentence? In chemistry

Readme [11.4K]

Answer:

Arrhenius has pointed out that the coefficient of affinity of an acid is proportional to its electrolytic ionization.

Explanation:

4 0

3 years ago