Which of the following molecules or ions has a bent shape?

In a first-order decomposition reaction. 58.6% of a compound decomposes in 11.7 min. How long (in min) does it take for 80.2% of

gavmur [86]

Answer:

t = 21.5 min.

Explanation:

Hello!

In this case, since the kinetics of a first-order reaction is:

$\frac{[A]}{[A]_0}=exp(-kt)$

Thus, since we are given the 11.7 min for a 58.6-% consumption, we can compute the rate constant, k:

$ln(1-0.586)=-kt\\\\k=\frac{ln(0.414)}{-t}=\frac{-0.882}{11.7min}=0.0754min^{-1}$

Now, for the second problem, as the new consumption is 80.2%, we can compute the required time as shown below:

$ln(1-0.802)=-kt\\\\t=\frac{ln(198)}{k} \\\\t=\frac{-1.62}{0.0754min^{-1}}\\\\t=21.5min$

Best regards!

6 0

2 years ago

One brand of extra-strength antacid tablets contains 750 mg of calcium carbonate (100 g/mol) in each tablet. Stomach acid is ess

konstantin123 [22]

Answer:

One tablet can neutralize 150 mL of stomach acid at a pH of 1.0

Explanation:

Step 1: Data given

Mass of calcium carbonate = 750 mg = 0.75 grams

Molar mass of CaCO3 = 100 g/mol

pH = 1.0

Step 2: The balanced equation

2HCl + CaCO3 → CaCl2 + H2CO3

Step 3: Calculate molarity of HCl

pH = -log[H+] = 1

[H+] = 0.1 M = 0.10 mol/L

Step 4: Calculate moles of CaCO3

Moles CaCO3 = 0.75 grams / 100g/mol

Moles CaCO3 = 0.0075 mol

Step 5: Calculate moles of HCl

For 2 moles HCl we need 1 mol CaCO3 to produce CaCl2 and 1 mole of H2CO3

For 0.0075 moles of CaCO3 we have 2*0.0075 = 0.015 moles HCl

Step 6: Calculate volume of HCl

Volume = moles /molarity

Volume = 0.015 moles / 0.1 M

Volume = 0.15 L = 150 mL

One tablet can neutralize 150 mL of stomach acid at a pH of 1.0.

6 0

2 years ago

1 - 2Na + O2 ➔ Na2O Balanced Not Balanced

Mrrafil [7]

Answer:

1 not

2 not

3 not

4 balanced

5 not

6 not

7 balanced

Explanation:

the amount of elements must be equal in the reactant and products

5 0

2 years ago

A sample of chlorine containing isotopes of mass numbers 35 and 37 was analysed in a mass-spectrometer. How many peaks correspon

Zolol [24]

Three peaks corresponding to Cl+2 will be recorded. The peaks are for isotope 35, both 35 and 37 and for isotope 37. Mass spectrometer has the ability to detect and separate isotopes, even those differing by a single atomic mass unit. When chlorine isotopes are analysed by mass spectrometer, either peak M or M+2 can be obtained. The intensity ratio in the isotope pattern depends on the natural abundance of the isotopes.

3 0

2 years ago

Carbon-14 (14C) dating assumes that the carbon dioxide on the Earth today has the same radioactive content as it did centuries a

Nataly [62]

<u>Answer:</u> The tree was burned 16846.4 years ago to make the ancient charcoal

<u>Explanation:</u>

The equation used to calculate rate constant from given half life for first order kinetics:

$t_{1/2}=\frac{0.693}{k}$