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3 years ago

If Chris throws the baseball 60 meters in 4 seconds what is the average speed of the football

1 answer:

4 0

Average speed (aka average velocity) is the change in displacement (distance) over the chance in time. $\frac{60 m}{4 sec}= V. V=15 m/sec$ The average velocity of the baseball is 15 meters/sec

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Help me on number 4 and that last one says blood pressure

Lyrx [107]

Map map map map map he keeps us on track when I leave home he go me back

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4 years ago

Calculate the pH of a solution that contains 2.7 M HF and 2.7 M HOC6H5. Also, calculate the concentration of OC6H5- in this solu

borishaifa [10]

Answer:

$\large \boxed{\mathbf{1.36; 3.6 \times 10^{\mathbf{-9}}}\textbf{mol/L}}$

Explanation:

The HF is about five million times as strong as phenol, so it will be by far the major contributor of hydronium ions. We can ignore the contribution from the phenol.

1 .Calculate the hydronium ion concentration

We can use an ICE table to organize the calculations.

HF + H₂O ⇌ H₃O⁺ + F⁻

I/mol·L⁻¹: 2.7 0 0

C/mol·L⁻¹: -x +x +x

E/mol·L⁻¹: 2.7 - x x x

$K_{\text{a}} = \dfrac{\text{[H}_{3}\text{O}^{+}] \text{F}^{-}]} {\text{[HF]}} = 7.2 \times 10^{-4}\\\\\dfrac{x^{2}}{2.7 - x} = 7.2 \times 10^{-4}\\\\\text{Check for negligibility of }x\\\\\dfrac{2.7}{7.2 \times 10^{-4}} = 4000 > 400\\\\\therefore x \ll 2.7\\\dfrac{x^{2}}{2.7} = 7.2 \times 10^{-4}\\\\x^{2} = 2.7 \times 7.2 \times 10^{-4} = 1.94 \times 10^{-3}\\x = 0.0441\\\text{[H$_{3}$O$^{+}$]}= \text{x mol$\cdot$L$^{-1}$} = \text{0.0441 mol$\cdot$L$^{-1}$}$

2. Calculate the pH

$\text{pH} = -\log{\rm[H_{3}O^{+}]} = -\log{0.0441} = \large \boxed{\mathbf{1.36}}$

3. Calculate [C₆H₅O⁻]

C₆H₅OH + H₂O ⇌ C₆H₅O⁻ + H₃O⁺

2.7 x 0.0441

$K_{\text{a}} = \dfrac{0.0441x} {2.7} = 1.6 \times 10^{-10}\\\\0.0441x = 1.6 \times 10^{-10}\\x = \dfrac{1.6 \times 10^{-10}}{0.0441} = \mathbf{3.6 \times 10^{\mathbf{-9}}}\textbf{ mol/L}\\\text{The concentration of phenoxide ion is $\large \boxed{\mathbf{3.6 \times 10^{\mathbf{-9}}}\textbf{ mol/L}}$}$

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4 years ago

The North Pole of a magnet will attract to the South Pole of another magnet. True or False

hodyreva [135]

pretty sure its True hope this helped

Explanation:

A magnet has two ends called poles; one end is the north pole and the other is the south pole. A north pole will attract a south pole; the magnets pull on each other. But the two north poles will push each other away. ... The magnet is attracted by the earth's magnetic north pole and always points in that direction.

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3 years ago

The atomic mass of hydrogen-1 is 1.008 and the atomic mass of helium-4 is 4.003. Find the difference in grams between 4 moles of

CaHeK987 [17]

4 moles of hydrogen = 4 * 1.008 = 4.032 grams

1 mole of helium = 4.003 grams

Difference is 4.032 - 4.003

= 0.029 g

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4 years ago

Read 2 more answers

How many protons, neutrons, and electrons are in Uranium-232? How many protons, neutrons, and electrons are in Uranium-232?

QveST [7]

Protons/Electrons: 92

Neutrons: 140

***REMEMBER: There is always the same amount of protons and electrons. :)

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3 years ago