The atomic number of sodium (Na) is 11. This is also the number of which of the following?

a 9.84 ounces ingot of unknown metal is heated from 73.2 degrees fahrenheit - 191.2 degrees fahrenheit this requires 3.912 calor

Gekata [30.6K]

The SI unit of specific heat is J per gram per degree Celsius. Thus it follows that specific heat could be calculated in this way:

Specific Heat = Energy / (mass x change in temperature)

Thus,

Specific Heat = 3.912 cal / (9.84 oz x (191.2 ˚F – 73.2 ˚F))

Specific Heat = 3.369 x 10^-3 cal/oz-˚F

6 0

4 years ago

A buffer with a pH of 4.31 contains 0.31 M of sodium benzoate and 0.24 M of benzoic acid. What is the concentration of [ H 3 O ]

Mnenie [13.5K]

<u>Answer:</u> The hydronium ion concentration in the solution is $1.29\times 10^{-4}M$

<u>Explanation:</u>

To calculate the molarity, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}$

Moles hydrochloric acid solution = 0.060 mol

Volume of solution = 1 L

Putting values in above equation, we get:

$\text{Molarity of HCl}=\frac{0.060}{1L}\\\\\text{Molarity of HCl}=0.060M$

The chemical reaction for aniline and HCl follows the equation:

$C_6H_5COO^-+HCl\rightarrow C_6H_5COOH+Cl^-$

<u>Initial:</u> 0.24 0.060 0.31

<u>Final:</u> 0.18 - 0.37

To calculate the pH of acidic buffer, we use the equation given by Henderson Hasselbalch:

$pH=pK_a+\log(\frac{[\text{conjugate acid}]}{[\text{base}]})$

$pH=pK_a+\log(\frac{[C_6H_5COO^-]}{[C_6H_5COOH]})$

We are given:

$pK_a$ = negative logarithm of acid dissociation constant of benzoic acid = 4.2

$[C_6H_5COO^-]=0.18M$

$[C_6H_5COOH]=0.37M$

pH = ?

Putting values in equation 1, we get:

$pH=4.2+\log(\frac{0.18}{0.37})\\\\pH=3.89$

To calculate the hydronium ion concentration in the solution, we use the equation:

$pH=-\log[H_3O^+]$

pH = 3.89

Putting values in above equation, we get:

$3.89=-\log[H_3O^+]$

$[H_3O^+]=10^{-3.89}=1.29\times 10^{-4}M$

Hence, the hydronium ion concentration in the solution is $1.29\times 10^{-4}M$

3 0

3 years ago

What property of water is primary for living organisms? (SC.6.E.7.4) *

joja [24]

Answer: it is liquid at most temperatures on earth.

Step-by-step explanation:

3 0

3 years ago

Read 2 more answers

Which two reactants make Calcium carbonate?

Norma-Jean [14]

Impossible to form from given reactants

Explanation:

Only sodium has carbonate ion here .so only possible way to displace carbonate is to use potassium

When sodium carbonate and Potassium iodide react with each other double displacement reaction occurs

As potassium is powerful than sodium it displaces sodium to form potassium carbonate .

Then you have to use water and then you can use calcium suppliment .

3 0

2 years ago

Read 2 more answers

Pulses A, B, C, and D all travel at 10 m/s on the same string but in opposite directions. The string is depicted at time t=0 in

Anit [1.1K]

(a) The displacement of point P at time t=0.10s is determined as +2cm.

(b) The displacement of point P at time t=0.20s is determined as -2cm.

<h3>What is displacement?</h3>

Displacement is the change in position of an object. It is obtained from the product of velocity and time of motion.

x = vt

<h3>Displacement of the waves after 0.1 s</h3>

x = 10 m/s x 0.1 s = 1 m

Each wave will travel 1 m to the right or to the left, depending on the initial direction.

wave B from left will stop at point 0 m
wave A from left will stop at point -1 m
wave C from right will stop at point 0 m
wave D from right will stop at point + 1 m

wave B and C superimposed and the displacement will be between A and D.

Amplitude of A = - 2cm

Amplitude of D = + 4cm

Displacement of point P = 4 cm - 2 cm = 2cm

<h3>Displacement of the waves after 0.2 s</h3>

x = 10 m/s x 0.1 s = 2 m

Each wave will travel 2 m to the right or to the left, depending on the initial direction.

wave B from left will stop at point 1 m
wave A from left will stop at point 0 m
wave C from right will stop at point -1 m
wave D from right will stop at point 0 m

Displacement of point P = (amplitude B + amplitude C) + (amplitude A + amplitude D)

Displacement of point P= (2cm - 2cm) + (2 cm - 4cm)= -2cm

Learn more about displacement here: brainly.com/question/2109763

#SPJ1

8 0

2 years ago