State which separation method you would use to separate potassium iodine solution

How many molecules of N2 are in a 400.0 mL container at 780 mm Hg and 135°C? Avogadro’s number = 6.022 x 1023A) 7.01 × 1021 mole

ASHA 777 [7]

Answer:

B

Explanation:

Firstly, we will need to calculate the number of moles. To do this, we make use of the ideal gas equation

PV = nRT

n = PV/RT

The parameters have the following values according to the question:

P = 780mmHg, we convert this to pascal.

760mHG = 101325pa

780mmHg = xpa

x = (780 * 101325)/760 = 103,991 Pa

V= 400ml = 0.4L

T = 135C = 135 + 273.15 = 408.15K

n = ?

R = 8314.463LPa/K.mol

Substituting these values into the equation yields the following:

n = (103991 * 0.4)/(8314.463 * 408.15)

= 0.012 moles

Now we know 1 mole contains 6.02 * 10^23 molecules, hence, 0.012moles will contain = 0.012 * 6.02 * 10^23 = 7.38 * 10^21 molecules

8 0

3 years ago

Read 2 more answers

1.Grassland are where most of our_____ comes from?

Dafna11 [192]

Answer is B.crops used as food

3 0

4 years ago

Read 2 more answers

The equilibrium reaction below has the Kc = 0.254 at 25°C. If the temperature of the system at equilibrium is decreased to 0°C,

tia_tia [17]

Answer:

The equilibrium shifts towards reagents

Explanation:

Is known $Kc=\frac{[products]}{[reagents]}$ rised to the power of their number of moles in the balanced reaction. When you have a system at equilibrium with Kc < 1, it means [products] < [reagents] and the system needs energy to react, so if you decrease tempeture the equilibrium shifts towards reagents and less products will be created.

This efect can be discribed with Van´t Hoff equation: $ln(\frac{K1}{K2}) =-\frac{dH}{R} (\frac{1}{T1} -\frac{1}{T2} )$ where we can see that if we decrease temperature (this is T2<T1) in consecuense K2<K1 and reaction doesn´t happen.

7 0

3 years ago

Calculate the volume of 12.0 g of helium at 100°c and 1.2 atm

hodyreva [135]

Volume = nRT/P

n = number of particles (moles)

R = universal gas constant (0.0821)

T = temperature (Kelvin)

P = pressure (atm)

(Assuming you have 1 mole of Helium in a chemical reaction) We would need to convert grams to moles: 12.0g He x 1 mol He/4 molar mass of He = 3 mol He

Convert Celsius to Kelvin: 100*C + 273.15 = 373.15 K

Now we can set up the equation for volume: (3mol)(0.0821)(373.15)/1.2atm = 76.6 L of Helium gas

8 0

3 years ago

2.3 Zinc has five naturally occurring isotopes: 48.63% of 64 Zn with an atomic weight of 63.929 amu; 27.90% of 66Zn with an atom

lakkis [162]

Answer: The average atomic mass of element Zinc is 65.40 amu.

Explanation:

Average atomic mass of an element is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.

Formula used to calculate average atomic mass follows:

$\text{Average atomic mass }=\sum_{i=1}^n\text{(Atomic mass of an isotopes)}_i\times \text{(Fractional abundance})_i$ .....(1)