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3 years ago

How many protons, electrons, and neutrons does the following isotope contain? ^{18} \text{F}^{-} 18 F −

1 answer:

8 0

Isotope ¹⁸F⁻ contains:
1) p⁺ = 9; number of protons.
Fluorine has atomic number Z = 9 (total number of protons).
2) e⁻ = 10; number of electrons.
In element number of electrons and protons are the same, because element has neutral charge, but because in this example, fluorine is anion with negative charge, it has one electron more.
3) n° = 9; number of neutrons.
Mass number A = 18 is total number of protons and neutrons in a nucleus, so number of neutrons is A-Z = 18-9=9.

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Briefly describe how a potentiometric pHmeter works. (Hint: Describe how the pH meter

liq [111]

Answer:

A general instrument, which is used to determine the concentration of hydrogen ion within the aqueous solution is known as a pH meter. The meter helps in determining the alkalinity or acidity, which is articulated in the form of pH. It is also called a potentiometric pH meter as it helps in finding the variation in electrical potential between a reference electrode and a pH electrode. This electrical potential variation is associated with the pH of the solution.

The potentiometric pH meter comprises a pair of electrodes and a basic electronic amplifier, some may even comprise a combination electrode and some sort of display that demonstrates pH units. The potentiometric pH meter generally exhibits a reference electrode or a combination electrode, and a glass electrode. The probes or electrodes are administered within a solution whose pH values are needed to be determined.

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3 years ago

What volume of carbon dioxide, at 1 atm pressure and 112°C, will be produced when 80.0 grams of methane is burned?

Vadim26 [7]

Answer:

158 L.

Explanation:

What is given?

Pressure (P) = 1 atm.

Temperature (T) = 112 °C + 273 = 385 K.

Mass of methane CH4 (g) = 80.0 g.

Molar mass of methane CH4 = 16 g/mol.

R constant = 0.0821 L*atm/mol*K.

What do we need? Volume (V).

Step-by-step solution:

To solve this problem, we have to use ideal gas law: the ideal gas law is a single equation which relates the pressure, volume, temperature, and number of moles of an ideal gas. The formula is:

$PV=nRT.$

Where P is pressure, V is volume, n is the number of moles, R is the constant and T is temperature.

So, let's find the number of moles that are in 80.0 g of methane using its molar mass. This conversion is:

$80.0g\text{ CH}_4\cdot\frac{1\text{ mol CH}_4}{16\text{ g CH}_4}=5\text{ moles CH}_4.$

So, in this case, n=5.

Now, let's solve for 'V' and replace the given values in the ideal gas law equation:

$V=\frac{nRT}{P}=\frac{5\text{ moles }\cdot0.0821\frac{L\cdot atm}{mol\cdot K}\cdot385K}{1\text{ atm}}=158.04\text{ L}\approx158\text{ L.}$

The volume would be 158 L.

6 0

1 year ago

how many grams of potassium chloride, KCL(molar mass is 74.55g/mol) are produced if 25 grams of potassium chlorate KClo^3 decomp

JulsSmile [24]

Answer:

Mass = 15.20 g of KCl

Explanation:

The balance chemical equation for the decomposition of KClO₃ is as follow;

2 KClO₃ = 2 KCl + 3 O₂

Step 1: Calculate moles of KClO₃ as;

Moles = Mass / M/Mass

Moles = 25.0 g / 122.55 g/mol

Moles = 0.204 moles

Step 2: Find moles of KCl as;

According to equation,

2 moles of KClO₃ produces = 2 moles of KCl

So,

0.204 moles of KClO₃ will produce = X moles of KCl

Solving for X,

X = 2 mol × 0.204 mol / 2 mol

X = 0.204 mol of KCl

Step 3: Calculate mass of KCl as,

Mass = Moles × M.Mass

Mass = 0.204 mol × 74.55 g/mol

Mass = 15.20 g of KCl

6 0

4 years ago

An inverted pyramid is being filled with water at a constant rate of 45 cubic centimeters per second. The pyramid, at the top, h

vaieri [72.5K]

Answer:

13.20 cm/s is the rate at which the water level is rising when the water level is 4 cm.

Explanation:

Length of the base = l

Width of the base = w

Height of the pyramid = h

Volume of the pyramid = $V=\frac{1}{3}lwh$

We have:

Rate at which water is filled in cube = $\frac{dV}{dt}= 45 cm^3/s$

Square based pyramid:

l = 6 cm, w = 6 cm, h = 13 cm

Volume of the square based pyramid = V

$V=\frac{1}{3}\times l^2\times h$

$\frac{l}{h}=\frac{6}{13}$

$l=\frac{6h}{13}$

$V=\frac{1}{3}\times (\frac{6h}{13})^2\times h$

$V=\frac{12}{169}h^3$

Differentiating V with respect to dt:

$\frac{dV}{dt}=\frac{d(\frac{12}{169}h^3)}{dt}$

$\frac{dV}{dt}=3\times \frac{12}{169}h^2\times \frac{dh}{dt}$

$45 cm^3/s=3\times \frac{12}{169}h^2\times \frac{dh}{dt}$

$\frac{dh}{dt}=\frac{45 cm^3/s\times 169}{3\times 12\times h^2}$

Putting, h = 4 cm

$\frac{dh}{dt}=\frac{45 cm^3/s\times 169}{3\times 12\times (4 cm)^2}$

$=13.20 cm/s$

13.20 cm/s is the rate at which the water level is rising when the water level is 4 cm.

3 0

3 years ago

25 points!!! please Which types of elements areconsidered neutraland Where are these types of elements found on the periodic tab

posledela

Elements which composed of an equal amount of three components protons, neutrons and electrons are considered neutral elements. example of neutral elements are hydrogen, helium, lithium and beryllium...

7 0

3 years ago