How many white blood cells does a normal adult with 5 L of blood have?

As water is cooled from 4º C to 0°C, its density

frosja888 [35]

Answer:

decreases

Explanation:

3 0

4 years ago

In the laboratory you are asked to make a 0.175 m barium iodide solution using 13.9 grams of barium iodide. How much water shoul

BARSIC [14]

Answer: The mass of water that should be added in 203.07 grams

Explanation:

To calculate the molality of solution, we use the equation:

$\text{Molality}=\frac{m_{solute}\times 1000}{M_{solute}\times W_{solvent}\text{ (in grams)}}$

Where,

m = molality of barium iodide solution = 0.175 m

$m_{solute}$ = Given mass of solute (barium iodide) = 13.9 g

$M_{solute}$ = Molar mass of solute (barium iodide) = 391.14 g/mol

$W_{solvent}$ = Mass of solvent (water) = ? g

Putting values in above equation, we get:

$0.175=\frac{13.9\times 1000}{391.14\times W_{solvent}}\\\\W_{solvent}=\frac{13.9\times 1000}{391.14\times 0.175}=203.07g$

Hence, the mass of water that should be added in 203.07 grams

4 0

3 years ago

The molar mass of H2O is 18.01 g/mol. The molar mass of O2 is 32.00 g/mol. What mass of H2O, in grams, must react to produce 50.

snow_lady [41]

112.5 g. The production of 50.00 g O2 requires 112.5 g H2O.

a) Write the partially balanced equation for the decomposition of water.

MM = 18.02 32.00

2H2O → O2 + …

Mass/g = 50.00

b) Calculate the moles of O2

Moles of O2 = 50.00 g O2 × (1 mol O2/16.00 g O2) = 3.1250 mol O2

c) Calculate the moles of water

Moles of H2O = 3.1250 mol O2 × (2 mol H2O/1 mol O2)

= 6.2500 mol H2O

d) Calculate the mass of water

Mass of H2O = 6.2500 mol H2O × (18.02 g H2O/1 mol H2O)

= 112.5 g H2O

5 0

3 years ago

The octet rule states that all atoms would like to have 8 electrons in their last shell with no exceptions! true or false

Montano1993 [528]

True due to the fact that eight electrons are what applies directly to the octet rule

7 0

3 years ago

The energy gap between the valence band and the conduction band in the widely-used semiconductor gallium arsenide (GaAs) is Δ =

stira [4]

Answer:

$n_e = 8.139 *10^6$

Explanation:

Given that;

The energy gap between the valence band and the conduction band in the widely-used semiconductor gallium arsenide (GaAs) is Δ = 1.424 eV.

So; that implies that:

$\delta \ E = 1.424 \ eV$

Suppose that we consider a small piece of GaAs with 1020 available electrons, -- This is taking about the numbers of electrons used which is :

$n_i = 10^{20} \ electrons$

Temperature is given as:

$T = 274.15 \ K$

Number of electrons can be calculated by using the formula;

$n_e = n_i*e^-^{\frac{\delta E }{2 K_B*T}}$

$n_e = 10^{20}*e^-^{\frac{1.424}{2*8.617*10^{-5}*274.15}}$

$n_e = 8.139 *10^6$

8 0

3 years ago