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2 years ago

Three most common alkali metals include:

Chemistry

2 answers:

QveST [7]2 years ago

4 0

Answer:

Sodium, potassium, and rubidium

Explanation:

The relative abundances in the Earth’s crust are:

Na = 2.6 %; K = 2.4 %; Rb = 60 ppm; Li = 17 ppm; Cs = 3 ppm; Fr ≈ 0 ppb

Leona [35]2 years ago

3 0

Sodium, Potassium, and Cesium

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Will give brainlist need answers asap

Serga [27]

Answer:

40 g

Explanation:

Find the line labeled KClO3 (which might take you a min, theres a lot of lines here)

Notice that when the line creates a direct point, you can measure the exact temperature needed to dissolve a certain amount (like how they gave 30 degrees and it lined up perfectly with the 10 g line. )

Since its asking for the amount at 80 degrees, all you need to do is trace the line to the 80 degree point, and look at the grams. (notice it made a direct point, so there definitely should be any decimals or guesswork)

By reading the graph, you can tell that at 80 degrees, it dissolves 40 grams, and that is your answer.

Hope this helps :)

3 0

2 years ago

Consider the following unbalanced reaction: P4(s) + F2(g) → PF3(g) What mass of fluorine gas is needed to produce 120. g of PF3

Studentka2010 [4]

Answer:

44.28 grams.

Explanation:

Let us write the balanced reaction:

$P_{4}+6F_{2}-->4PF_{3}$

As per balanced equation, six moles of fluorine gas will give four moles of PF₃.

The mass of PF₃ required = 120 g

The molar mass of PF₃ = 88g/mol

Moles of PF₃ required = $\frac{mass}{molarmass}=\frac{120}{88}=1.364mol$

The moles of fluorine gas required = $\frac{4X1.364}{6}=0.91$

the mass of fluorine gas required = moles X molar mass = 0.91x38 = 34.58g

Now this much mass will be required if the reaction is of 100% yield

But as given that the yield of reaction is only 78.1%

The mass of fluorine required = $\frac{massX100}{78.1} =\frac{34.58X100}{78.1} =44.28g$

4 0

3 years ago

En un matraz, disponemos de 100 g de gas oxígeno que se encuentran a 1 at de presión y 273 K de temperatura. Calcular : a) el nú

Misha Larkins [42]

Answer:

Explanation:

Dado que:

masa de oxígeno gaseoso = 100 g

presión = 1 atm

temperatura = 273 K

(a)

número de moles de oxígeno contenidos en el matraz = masa de oxígeno / masa molar de oxígeno

= 100 g / 16 gmol⁻¹

= 6.25 moles

(b) El número de moléculas de oxígeno es el siguiente:

Dado que 1 mol de oxígeno gaseoso contiene 6.023 * 10²³ moléculas de oxígeno.

Entonces, 6.25 moles contendrán:

= (6.25 × 6.023 * 10²³) moléculas de oxígeno.

≅ 3.764 × 10²³ moléculas de oxígeno.

= 2 × 3.764 × 10²³

= 7.528 × 10²³ átomos de oxígeno

(d) Usando la ecuación de gas ideal

PV = nRT

El volumen ocupado por el oxígeno = $\dfrac{nRT}{P}$

Volumen ocupado por oxígeno = $\dfrac{ 6.25 * 8.314 *273}{1}$

Volumen ocupado por oxígeno= 14185.76 m³

3 0

2 years ago

I need help!! PLease anyone?? <br><br> 3. critical point.<br><br> 4. Define critical pressure

andrezito [222]

Critical pressure is the pressure of a gas or vapor in its critical state and critical point is a point on a phase diagram at which both the liquid and gas phases of a substance have the same density, and are therefore indistinguishable.

6 0

3 years ago

It has been established that 8.0x10^4 tons of gold (Au) have been mined. Assume gold cost $350 per ounce. Whats the total worth

bazaltina [42]

So first lets find out how much gold there is. 10^4=10,000so that means 8.0x10,000= 8,000. now we have to find out how much money that is. All we have to do is multiply 8,000 by 350. When multiplied you get $2,800,000

7 0

2 years ago