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3 years ago

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The melting point of gallium metal is 29.76⁰C. If a piece of gallium is sliced into three parts, the melting point of each part

will be what A: higher than 29.76⁰C. B: 29.76⁰C. C: lower than 29.76⁰C

1 answer:

Ahat [919]3 years ago

7 0

Answer:

itd be B because the melting point is 29.76 no matter the size

Explanation:

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Which of the following is a type of cell organelle?

xz_007 [3.2K]

Answer:

Nucleas is a cell organelle

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3 years ago

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Que. 1. Gallium has 2 naturally occuring Isotopes with mass numbers 69 & 71 respectively. What is the percentage abundance o

IgorC [24]

Isotopes are atoms of the same element that have different masses. The relative atomic mass (am) is a weighted average that takes into account the abundance of each isotope. We can calculate the relative atomic mass using the following expression.

$am = \frac{\Sigma m_i \times ab_i}{100}$

where,

mi: mass of each isotope

abi: percent abundance of each isotope

For Gallium,

$70.59 amu = \frac{69 amu\ x + 71 amu\ y}{100}$ [1]

where "x" and "y" are the unknown abundances.

We also know that the sum of both abundances must be 100%.

x + y = 100

y = 100 - x [2]

If we replace [2] in [1], we get

$70.59 amu = \frac{69 amu\ x + 71 amu\ (100-x)}{100} \\7059 amu = -2 amu\ x + 7100amu \\x = 20.5$

Then, in [2]

y = 100 - x = 100 - 20.5 = 79.5

In conclusion, Ga-69 has an abundance of 20.5% and Ga-71 has an abundance of 79.5%.

You can learn more about isotopes in: brainly.com/question/21536220?referrer=searchResults

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3 years ago

Un mol de amoniaco Tiene una masa molar de 17 g y ocupa un volumen de 22.4 l qué volumen ocupa el 50 g amoniaco en condiciones n

mr_godi [17]

Answer:

V = 65.81 L

Explanation:

En este caso, debemos usar la expresión para los gases ideales, la cual es la siguiente:

PV = nRT (1)

Donde:

P: Presion (atm)

V: Volumen (L)

n: moles

R: constante de gases (0.082 L atm / mol K)

T: Temperatura (K)

De ahí, despejando el volumen tenemos:

V = nRT / P (2)

Sin embargo como estamos hablando de condiciones normales de temperatura y presión, significa que estamos trabajando a 0° C (o 273 K) y 1 atm de presión. Lo que debemos hacer primero, es calcular los moles que hay en 50 g de amoníaco, usando su masa molar de 17 g/mol:

n = 50 / 17 = 2.94 moles

Con estos moles, reemplazamos en la expresión (2) y calculamos el volumen:

V = 2.94 * 0.082 * 273 / 1

<h2>V = 65.81 L</h2>

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3 years ago

Calculate the osmotic pressure associated with 50.0 g of an enzyme of molecular weight 98 g/mol dissolved in water to give 2600

andrew-mc [135]

Answer:

π = 4,882 atm

Explanation:

To calculate the osmotic pressure (π), the <em>Van´t Hoff equation</em> must be used, which is:

π x V = n x R x T

<em>Where: </em>

• π: Osmotic pressure, which is the difference between the levels of the solution and the pure solvent through a semipermeable membrane, which allows the passage of the solvent but not the solute

• V: Volume of the solution, in liters unit

• n: Number of moles of solute

• R: Constant of ideal gases, equal to 0.08206 L.atm / mol.K

• T: Absolute temperature, in Kelvin degrees

With the data you provide you can calculate the osmotic pressure by clearing it from the equation, we would be equal to:

π = (n x R x T) / V

However, all data must first be converted to the corresponding units in order to replace the values in the equation.

<em>Solution volume ⇒ go from mL to L: </em>

1000 mL of solution ____ 1 L

2600 mL of solution _____ X = 2.6 L

Calculation: 2600 mL x 1 L / 1000 mL = 2.6 L

<em>Temperature ⇒ Go from ° C to K </em>

T (K) = t (° C) + 273.15 = 30.0 ° C + 273.15 = 303.15 K

<em>Number of moles of solute ⇒</em> <em>It can be calculated since we have the mass of the enzyme and its molecular mass: </em>

98.0 g of enzyme ____ 1 mol

50.0 g of enzyme _____ X = 0.510 moles

Calculation: 50.0 g x 1 mol / 98.0 g = 0.510 moles

Now, you can replace the values in the Van´t Hoff equation and you will get the result:

π = (n x R x T) / V

π = (0.510 mol x 0.08206 L.atm / mol.K x 303.15 K) / 2.6 L = 4.882 atm

Therefore, <em>the osmotic pressure will be 4,882 atm</em>

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3 years ago

Sterling silver is 92.5% silver and 7.5% copper. Its density is 10.25 g/cm3. A sterling silver pendant is added to a graduated c

Mariulka [41]

From the information given:

The volume of the graduated cylinder = 50.0 mL
when a sterling silver pendant is added, the volume increases to = 61.3 mL

∴

The volume of the sterling silver pendant is:

= 61.3 mL - 50.0 mL

= 11.3 mL

Since, 1 mL = 1cm³

Then;

11.3 mL = 11.3 cm³

the density of the sterling silver = 10.25 g/cm³

Using the relation for Density; i.e.

$\mathbf{Density = \dfrac{mass}{volume}}$

$\mathbf{10.25 \ g/cm^3= \dfrac{mass}{11.3 \ cm^3}}$

mass = 10.25 g/cm³× 11.3 cm³

mass of the sterling silver = 115.825 grams

Recall that sterling silver has:

92.5% silver and;
7.5% copper

∴

The mass of the copper contained in the sterling silver pendant can be calculated as:

$\mathbf{= \dfrac{115.825 \ g \times 7.5}{100}}$

= 8.687 grams

Therefore, we can conclude that the mass of the copper contained in the sterling silver pendant is 8.687 grams

Learn more about the relation between Density, Mass, and Volume here:

brainly.com/question/24386693?referrer=searchResults

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2 years ago