How many significant figures are present in 2.020 x 10-25

List the following carboxylic acid derivatives in decreasing order of reactivity in nucleophilic acyl substitution reactions: ac

kondor19780726 [428]

Answer:

<h2>acetyl chloride > acetic anhydride > methyl acetate > acetamide</h2>

Explanation:

Such kind of substitution reaction in which nucleophiles and the acyl compound interact is known as nucleophilic acyl substitution reaction. In this reaction, the interaction between carbonyl compounds and the nucleophile takes place by addition reaction. The reactivity of the acyl compound is based on the condition of the leaving group that is related to the acidity of the compounds. So the decreasing order of reactivity of the acyl compounds is, acetyl chloride > acetic anhydride > methyl acetate > acetamide.

5 0

4 years ago

Describe the walls of Antelope Canyon. · How was Antelope Canyon made? · Why is water vapor invisible? · How is rain formed in d

Monica [59]

1. Antelope Canyon was formed by the erosion of Navajo Sandstone.

2. The appearance of water is determined

by the way the water molecules are moving.

3. Moist rising air near the Equator cools and condenses into clouds and, later, rain.

6 0

4 years ago

The daily output of stomach acid (gastric juice) is 1000 to 2000 mL. Prior to a meal, stomach acid (HCl) typically has a pH of 1

Semmy [17]

Answer:

B.) 2 HCl(aq) + CaCO₃(s) → CaCl₂(aq) + H₂O(l) + CO₂(g)

C.) 7.4 × 10² mL

D.) 2 HCl(aq) + Mg(OH)₂(aq) → MgCl₂(aq) + H₂O(l)

E.) 1.3 × 10³ mL

Explanation:

The daily output of stomach acid (gastric juice) is 1000 to 2000 mL. Prior to a meal, stomach acid (HCl) typically has a pH of 1.49.

We can calculate the concentration of H⁺ using the definition of pH.

pH = -log [H⁺]

[H⁺] = antilog -pH = antilog (-1.49) = 0.0324 M

Since HCl is a strong monoprotic acid, we can consider this to be the concentration of HCl as well.

B.) One chewable tablet of the antacid Maalox contains 600 mg of CaCO₃. Enter the neutralization equation. Express your answer as a molecular equation including phases.

The neutralization equation is:

2 HCl(aq) + CaCO₃(s) → CaCl₂(aq) + H₂O(l) + CO₂(g)

C.) Given that one chewable tablet of the antacid Maalox contains 600 mg of CaCO₃, calculate the milliliters of stomach acid neutralized by two tablets of Maalox. Express the volume in milliliters to two significant figures.

We can establish the following relations:

Each tablet has 600 mg (0.600 g) of CaCO₃.
The molar mass of CaCO₃ is 100.09 g/mol.
The molar ratio of HCl to CaCO₃ is 2:1.
The concentration of HCl is 0.0324 mol/L.

The mililiters of HCl that neutralize 2 tablets of Maalox are:

$2Tablet.\frac{0.600gCaCO_{3}}{1Tablet} .\frac{1molCaCO_{3}}{100.09gCaCO_{3}} .\frac{2molHCl}{1molCaCO_{3}} .\frac{1000mLHCl}{0.0324molHCl} =7.4 \times 10^{2} mLHCl$

D.) The antacid milk of magnesia contains 400 mg of Mg(OH)₂ per teaspoon. Enter the neutralization equation. Express your answer as a molecular equation including phases.

The neutralization equation is:

2 HCl(aq) + Mg(OH)₂(aq) → MgCl₂(aq) + H₂O(l)

E.) Given that the antacid milk of magnesia contains 400 mg of Mg(OH)₂ per teaspoon, calculate the number of milliliters of stomach acid that are neutralized by 1 tablespoon of milk of magnesia. (1 tablespoon = 3 teaspoons.)Express the volume in milliliters to two significant figures.

We can establish the following relations:

1 tablespoon = 3 teaspoons
1 teaspoon contains 400 mg (0.400 g) of Mg(OH)₂
The molar mass of Mg(OH)₂ is 58.32 g/mol.
The molar ratio of HCl to Mg(OH)₂ is 2:1.
The concentration of HCl is 0.0324 mol/L.

The mililiters of HCl that neutralize 1 tablespoon of milf of magnesia are:

$1Tablespoon.\frac{3Teaspoon}{1Tablespoon} .\frac{0.400gMg(OH)_{2}}{1Teaspoon} .\frac{1molMg(OH)_{2}}{58.32gMg(OH)_{2}} .\frac{2molHCl}{1molMg(OH)_{2}} .\frac{1000mLHCl}{0.0324molHCl} =1.3 \times 10^{3} mLHCl$

4 0

3 years ago

"Calculate the pH during the titration of 30.00 mL of 0.1000 M C3H7COOH(aq) with 0.1000 M LiOH(aq) after 29.9 mL of the base hav

Ivanshal [37]

Answer:

pH = 7.29

Explanation:

Ka of butanoic acid is 1.54x10⁻⁵

To obtain the pH of the solution you must use H-H equation for butanoic acid:

pH = pKa + log₁₀ [C₃H₇COO⁻] / [C₃H₇COOH]

Where pKa is defined as -log Ka = 4.81

Now, you need to find [C₃H₇COO⁻] and [C₃H₇COOH] concentrations (Also, you can find moles of each substance and replace them in the equation.

Butanoic acid reacts with LiOH, producing C₃H₇COO⁻, thus:

C₃H₇COOH + LiOH → C₃H₇COO⁻ + H₂O + Li⁺

Moles of both reactants, C₃H₇COOH and LiOH are:

C₃H₇COOH = 0.0300L ₓ (0.1000mol / L) = 0.003000moles of C₃H₇COOH

LiOH = 0.0299L ₓ (0.1000mol / L) = 0.00299 moles of LiOH.

That means moles of C₃H₇COO⁻ produced are 0.00299 moles.

And moles of C₃H₇COOH that remains in solution are:

0.00300 - 0.00299 = 0.00001 moles of C₃H₇COOH

Replacing in H-H equation:

pH = pKa + log₁₀ [C₃H₇COO⁻] / [C₃H₇COOH]

pH = 4.81 + log₁₀ [0.00299moles] / [0.00001moles]

7 0

4 years ago

Which of the following elements is the smallest? A. Be B. Ca C. Sr D. Mg

alexandr402 [8]

Answer:

Option A. (Be)

Explanation:

Beryllium is used in alloys with copper or nickel to make gyroscopes, springs, electrical contacts, spot-welding electrodes and non-sparking tools.

7 0

3 years ago