Thank chu if you answer

A titration is performed on a 25.0 mL sample of calcium hydroxide. A volume of

slamgirl [31]

Answer:

$\boxed {\boxed {\sf 0.28 \ M}}$

Explanation:

Titration is a method used to determine the concentration of a substance. The formula for this is:

$M_AV_A= M_BV_B$

Where M is the molarity of the acid or base and V is the volume of the acid or base.

We know that 46.0 milliliters of a 0.15 molar solution of nitric acid wereused in the titration. 25.0 milliliters of solution of calcium hydroxide of unknown molarity were also used.

$\bullet \ M_A= 0.15 \ M \\\bullet \ V_A= 46.0 \ mL\\\bullet \ V_B= 25.0 \ mL$

Substitute these known values into the formula.

$0.15 \ M * 46.0 \ mL= M_B * 25.0 \ mL$

We are solving for the molarity of the base, so we must isolate the variable $M_B$ . It is being multiplied by 25.0 milliliters. The inverse operation of multiplication is division, so we divide both sides of the equation by 25.0 mL.

$\frac {0.15 \ M * 46.0 \ mL}{25.0 \ mL}= \frac{M_B * 25.0 \ mL}{25.0 \ mL}$

$\frac {0.15 \ M * 46.0 \ mL}{25.0 \ mL}= M_B$

The units of milliliters (mL) cancel.

$\frac {0.15 \ M * 46.0 }{25.0}=M_B$

$\frac {6.9}{25.0 } \ M =M_B$

$0.276 \ M = M_B$

The original measurements have 2 or 3 significant figures. We always round our answer to the least number of sig figs, which is 2. For the number we calculated, that is the hundredths place. The 6 in the thousandths place tells us to round the 7 up to an 8.

$0.28 \ M \approx M_B$

The concentration of calcium hydroxide is approximately 0.28 M.

6 0

3 years ago

Ammonia has been studied as an alternative "clean" fuel for internal combustion engines, since its reaction with oxygen produces

Alchen [17]

The question is incomplete, here is the complete question:

Ammonia has been studied as an alternative "clean" fuel for internal combustion engines, since its reaction with oxygen produces only nitrogen and water vapor, and in the liquid form it is easily transported. An industrial chemist studying this reaction fills a 5.0 L flask with 2.2 atm of ammonia gas and 2.4 atm of oxygen gas at 44.0°C. He then raises the temperature, and when the mixture has come to equilibrium measures the partial pressure of nitrogen gas to be 0.99 atm.

Calculate the pressure equilibrium constant for the combustion of ammonia at the final temperature of the mixture. Round your answer to 2 significant digits.

Answer: The pressure equilibrium constant for the reaction is 32908.46

Explanation:

We are given

Initial partial pressure of ammonia = 2.2 atm

Initial partial pressure of oxygen gas = 2.4 atm

Equilibrium partial pressure of nitrogen gas = 0.99 atm

The chemical equation for the reaction of ammonia and oxygen gas follows:

$4NH_3(g)+3O_2(g)\rightarrow 2N_2(g)+6H_2O(g)$

Initial: 2.2 2.4

At eqllm: 2.2-4x 2.4-3x 2x 6x

Evaluating the value of 'x':

$\Rightarrow 2x=0.99\\\\x=0.495$

So, equilibrium partial pressure of ammonia = (2.2 - 4x) = [2.2 - 4(0.495)] = 0.22 atm

Equilibrium partial pressure of oxygen gas = (2.4 - 3x) = [2.4 - 3(0.495)] = 0.915 atm

Equilibrium partial pressure of water vapor = 6x = (6 × 0.495) = 1.98 atm

The expression of $K_p$ for above equation follows:

$K_p=\frac{(p_{N_2})^2\times (p_{H_2O})^6}{(p_{NH_3})^4\times (p_{O_2})^3}$

Putting values in above equation, we get:

$K_p=\frac{(0.99)^2\times (1.98)^6}{(0.22)^4\times (0.915)^3}\\\\K_p=32908.46$

Hence, the pressure equilibrium constant for the reaction is 32908.46

5 0

3 years ago

explain why the hydrogen atoms in a hydrogen gas molecule form nonpolar covalent bonds but oxygen and hydrogen atoms in water mo

marishachu [46]

Answer:

Explanation:

Covalent bond:

It is formed by the sharing of electron pair between bonded atoms.

The atom with larger electronegativity attract the electron pair more towards itself and becomes partial negative while the other atom becomes partial positive.

Non polar covalent bond:

It is the bond where both bonded atoms share the pair of electron equally.

For example:

Hydrogen gas (H₂) is non polar covalent compound because the electronegativity of both bonded atoms are same. No poles are created that's why this is non polar covalent compound.

Polar covalent bond:

It is the bond where both bonded atoms share the pair of electron unequally.

For example:

In water the electronegativity of oxygen is 3.44 and hydrogen is 2.2. That's why electron pair attracted more towards oxygen, thus oxygen becomes partial negative and hydrogen becomes partial positive and bond is polar.

7 0

4 years ago

1.00 atm = 760 mm Hg. 5.00 atm = ___________ mm HG Select one: a. 5 b. 152 c. 3800 d. 3.34 X 1010

olasank [31]

Answer:

C

answer is 5×760 mm of Hg = 3800

8 0

3 years ago

Read 2 more answers

The dehydration of the alcohol functional group is a widely used reaction in organic chemistry. The mechanism is generally accep

puteri [66]

Answer:

Elimination
Elimination
Zaitsev
Zaitsev
Carbocation

Explanation:

The mechanism is generally accepted to always operate via an ELIMINATION step-wise process.

The ELIMINATION mechanism process will always produce (after dehydration) a ZAITSEV style alkene as major product

The driving force for the production of this ZAITSEV style alkene product is generally going to be determined by stability of the CARBOCATION

Elimination mechanism is the removal of two substituents from a molecule in either a one- or two-step mechanism

Carbocation is a molecule containing a positive charged carbon atom and three bonds

3 0

3 years ago