These are all chemistry questions please help

The density of ice is 920 kg/m3 and that of sea water is 1030 kg/m3 . what fraction of the total volume of an iceberg is exposed

Lyrx [107]

To be floating, the gravity force of the iceberg should be same as the buoyancy force that result from the difference of the ice and water density.
The density of ice is 920 and water is 1030, then the difference should be: 1030kg/m3-920kg/m3= 110kg/m3

Let say that the volume of ice below the water is volume1 and the volume above the water(exposed volume) is volume2.
You can get this equation

volume1+volume2= 100%
volume1= 100%- volume2

Insert it into the buoyancy and gravity force will result
buoyancy=gravity
110kg/m3*volume1= 920kg/m3 *volume2
110kg/m3*(100%- volume2)= 920kg/m3 *volume2
110kg/m3 - 110kg/m3*volume2= 920kg/m3 *volume2
110kg/m3 = 1030kg/m3 *volume2
volume2= 110/1030= 0.1067= 10.7%

7 0

3 years ago

If you purchased 0.610 μCi of sulfur-35, how many disintegrations per second does the sample undergo when it is brand new?Expres

ASHA 777 [7]

Answer:

the sample undergo $1.67 \times 10^5$ disintegrations per second.

Explanation:

Given:

The amount of sulphur purchased is 0.671 μCi

To find:

disintegrations per second = ?

Solution:

Some of the conversions are

$1 Ci = 3.8 \times 10^{10} Bq$

1 rad = 0.01 Gy

1Gy = 1 j/kg tissue

1 rem = 0.01 Sv

1Sv = 1 j/Kg

Using these conversions,

The decay rate of this sample is calculated as

$0.671 \mu C i \times \frac{1 \mu C i}{10^{6}} \mu C i \times \frac{0.671 \times 10^{10}}{1 \mu C i}$

= $1.67 \times 10^5$ disintegrations per second

7 0

4 years ago

What should be the mole fraction of O2 in the gas mixture the diver breathes in order to have the same partial pressure of oxyge

Nutka1998 [239]

The question is incomplete, here is the complete question:

A scuba diver is at a depth of 355 m, where the pressure is 36.5 atm.

What should be the mole fraction of $O_2$ in the gas mixture the diver breathes in order to have the same partial pressure of oxygen in his lungs as he would at sea level? Note that the mole fraction of oxygen at sea level is 0.209.