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3 years ago

15

Which of the following is a good scientific question?

1 answer:

LiRa [457]3 years ago

4 0

Answer:

What effect does the pH of water have on radish seed germination?

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Every bronsted-lowry acid is also a lewis acid True or False

fenix001 [56]

<h2><em>It is True that every bronsted-lowry acid is also a lewis acid </em></h2>

3 0

3 years ago

Calcium hydroxide is a strong base but is not very soluble ( Ksp = 5.02 X 10-6 ). What is the pH of a saturated solution of Ca(O

Misha Larkins [42]

Answer : The pH of a saturated solution is, 12.33

Explanation : Given,

$K_{sp}$ = $5.02\times 10^{-6}$

First we have to calculate the solubility of $OH^-$ ion.

The balanced equilibrium reaction will be:

$Ca(OH)_2\rightleftharpoons Ca^{2+}+2OH^-$

Let the solubility will be, 's'.

The concentration of $Ca^{2+}$ ion = s

The concentration of $OH^-$ ion = 2s

The expression for solubility constant for this reaction will be,

$K_{sp}=[Ca^{2+}][OH^-]^2$

Let the solubility will be, 's'

$K_{sp}=(s)\times (2s)^2$

$K_{sp}=(4s)^3$

Now put the value of $K_[sp}$ in this expression, we get the solubility.

$5.02\times 10^{-6}=(4s)^3$

$s=1.079\times 10^{-2}M$

The concentration of $Ca^{2+}$ ion = s = $1.079\times 10^{-2}M$

The concentration of $OH^-$ ion = 2s = $2\times (1.079\times 10^{-2}M)=2.158\times 10^{-2}M$

First we have to calculate the pOH.

$pOH=-\log [OH^-]$

$pOH=-\log (2.158\times 10^{-2})$

$pOH=1.67$

Now we have to calculate the pH.

$pH+pOH=14\\\\pH=14-pOH\\\\pH=14-1.67=12.33$

Therefore, the pH of a saturated solution is, 12.33

7 0

3 years ago

How many seconds does it take a race horse to run six furlongs at 40.7 miles per hour if: I furlong = 40 rods; 5.5 yards = 1 rod

lana [24]

Distance traveled by the race horse=6 furlongs

Converting the distance from furlongs to rods: 40 rods =1 furlong

$6 furlongs*\frac{40rods}{1furlong} =240rods$

Converting the distance from rods to yards, feet and miles: 5.5 yards = 1 rod, 3foot =1 yard, 1 mile = 5280 feet.

$240rods*\frac{5.5yards}{1rod}*\frac{3foot}{1yard}*\frac{1mi}{5280feet}=0.75mi$

The given speed of race horse = 40.7mi/hr

Calculating the time required:

$0.75mi*\frac{1hr}{40.7mi}*\frac{60min}{1hr}*\frac{60s}{1min}= 66.34s$

Therefore, 66.34 s is required for a race horse to run six furlongs at 40.7 miles per hour.

8 0

3 years ago

An increase in which of the following would increase the boiling point of a<br> liquid?

Doss [256]

Answer:

The boiling point increases with increased pressure up to the critical point, where the gas and liquid properties become identical.

5 0

3 years ago

If an isotope of an element has 40 neutrons and a mass number of 79, how many electrons must it have?

34kurt

Answer: 39 electrons

Explanation: Subtract 79 by 40 to get the atomic number (amount of protons) which is 39. The number of electrons must be the same as the number of protons if it's not an ionic compound so the amount of electrons is the same amount of protons.

5 0

3 years ago