All categories

3 years ago

What does Nb stand for on the periodic table? Pls help! Need aware soon

Chemistry

2 answers:

laila [671]3 years ago

7 0

It stands for niobium

Marina86 [1]3 years ago

4 0

It stands for niobium which was discovered in 1801 by Charles Hatchett of Brittan. It is ussed in welding rods, air fraim systems, superconductive magnets. It gets its name from iobe, the daughter of King Tantalus of the Greek myth. Niobium was considered identical to Tantalum, named after Tantalus, until 1884. Resists corrosin due to an oxide film. It is used in aviation industry

You might be interested in

Choose all the correct information concerning chemical reactions: Involves small amounts of energy. Some of the mass is converte

suter [353]

<span>A chemical reactions :
Involves small amounts of energy.
</span><span> Only electrons are involved.
</span><span>The mass remains the same.</span>

8 0

3 years ago

Read 2 more answers

Consider the relationship (y+3)2 = b/(x-2), where y and x are variables and bis a constant. On rectangular coordinate paper, wha

Nikolay [14]

Answer:

(-1) is the slope of a graph of In(y+3) on the vertical axis versus In(x-2) on the horizontal axis.

Explanation:

$\frac{(y+3)}{2} = \frac{b}{(x-2)}$

Taking natural logarithm on both the sides:

$\ln [(y+3)]-\ln[2]=\ln [b]-\ln [(x-2)]$

$\ln [(y+3)]=\ln[2]+\ln [b]-\ln [(x-2)]$

$\ln [(y+3)]=\ln {[2\times b]-\ln [(x-2)]$

Slope intercept form is generally given as:

$y=mx+c$

m = slope, c = intercept on y axis or vertical axis

On rearranging equation:

$\ln [(y+3)]=(-1)\times \ln [(x-2)]+\ln {2b}$

y = ln [(y+3)], x = ln [(x-2)], m=-1 , c = ln 2b

(-1) is the slope of a graph of In(y+3) on the vertical axis versus In(x-2) on the horizontal axis.

8 0

3 years ago

A 2.20 mol sample of NO 2 ( g ) is added to a 3.50 L vessel and heated to 500 K. N 2 O 4 ( g ) − ⇀ ↽ − 2 NO 2 ( g ) K c = 0.513

igor_vitrenko [27]

Answer:

[NO₂] = 0.434 M

[N₂O₄] = 0.0971 M

Explanation:

The equilibrum is: N₂O₄(g) ⇆ 2NO₂ (g)

1 moles of nitrogen (IV) oxide is in equilibrium with 2 moles of nitrogen dioxide.

Initally we only have 2.20 moles of NO₂. So let's write the equilibrium again:

2NO₂ (g) ⇆ N₂O₄(g)

Initially 2.20 mol -

React x x/2

X amount has reacted, and the half has been formed, according to stoichiometry.

Eq (2.20-x) / 3.50L (x/2)/ 3.50L

We divide by the volume because we need molar concentrations. Let's make the Kc's expression:

Kc = [N₂O₄] / [NO₂]²

0.513 = ((x/2)/ 3.50L) / [(2.20-x) / 3.50L]

0.513 = ((x/2)/ 3.50L) / [(2.20-x)² / 3.50L²]

0.513 = ((x/2)/ 3.50L) / [2.20-x)² / 3.50L²]

0.513 = ((x/2)/ 3.50L) / (4.84 - 4.40x + x²) / 12.25)

0.513 / 12.25 (4.84 - 4.40x + x²) = x/2 / 3.50

0.203 - 0.184x + 0.0419x² = x/2 / 3.50

3.50(0.203 - 0.184x + 0.0419x²) = x/2

7 (0.203 - 0.184x + 0.0419x²) - x = 0

1.421 - 2.288x + 0.2933x² = 0 → Quadratic formula

a = 0.2933 ; b = -2.288 ; c = 1.421

(-b +- √(b²-4ac)) / (2a)

x₁ = 7.12

x₂ = 0.68 → We consider this value, so we can have a (+) concentration.

Concentrations in the equilibrium are:

[NO₂] = (2.20-0.68) / 3.50 = 0.434 M

[N₂O₄] = (0.68/2) / 3.50 = 0.0971 M

8 0

3 years ago

Determine the molar mass of a 0.458-gram sample of gas having a volume of 1.20 l at 287 k and 0.980 atm. group of answer choices

lilavasa [31]

Considering the ideal gas law and the definition of molar mass, the molar mass of the sample of gas is 9.17 $\frac{g}{mol}$ .

<h3>Ideal gas law</h3>

An ideal gas is a theoretical gas that is considered to be composed of randomly moving point particles that do not interact with each other. Gases in general are ideal when they are at high temperatures and low pressures.

The pressure, P, the temperature, T, and the volume, V, of an ideal gas, are related by a simple formula called the ideal gas law:

P×V = n×R×T

where:

P is the gas pressure.
V is the volume that occupies.
T is its temperature.
R is the ideal gas constant. The universal constant of ideal gases R has the same value for all gaseous substances.
n is the number of moles of the gas.

<h3>Definition of molar mass</h3>

The molar mass of substance is a property defined as its mass per unit quantity of substance, in other words, molar mass is the amount of mass that a substance contains in one mole.

<h3>Molar mass of the sample of gas</h3>

In this case you know:

P= 0.980 arm
V= 1.20 L
T= 287 K
R= 0.082 $\frac{atmL}{molK}$
n= ?

Replacing in the ideal gas law:

0.980 atm× 1.20 L= n× 0.082 $\frac{atmL}{molK}$ × 287 K

Solving:

(0.980 atm× 1.20 L)÷ (0.082 $\frac{atmL}{molK}$ × 287 K)= n

<u><em>0.04997 moles= n</em></u>

On the other hand, you know that the<u><em> mass of the sample of gas</em></u> is <u><em>0.458 grams</em></u>. Replacing in the definition of molar mass:

$molar mass=\frac{0.458 grams}{0.04997 moles}$

Solving:

<u><em>molar mass= 9.17 </em></u> $\frac{g}{mol}$

Finally, the molar mass of the sample of gas is 9.17 $\frac{g}{mol}$ .

Learn more about

molar mass:

brainly.com/question/5216907

brainly.com/question/11209783

brainly.com/question/7132033

brainly.com/question/17249726

ideal gas law:

brainly.com/question/4147359

#SPJ1

6 0

2 years ago

Hey hiihhbdndkdkdjdjddjdj

grigory [225]

Answer:

4 cups are about 0.25 gallons

Explanation:

To convert a cup measurement to a gallon measurement, divide the volume by the conversion ratio. The volume in gallons is equal to the cups divided by 16.

7 0

3 years ago

Read 2 more answers