Answer:
Phase changes that require a loss in energy are condensation and freezing.
Explanation:
Answer:
THE LENGTH OF THE AIR COLUMN IS 9.5 CM
Explanation:
Taking the atmospheric pressure to be 760 mmHg;
When the capillary tube is held horizontally, the pressure of the tube is 760 mmHg
when the capillary tube is held vertically, the pressure increases by 4 cm = 40 mm
The new pressure of the tube is hence, 760 + 40 mmHg = 800 mmHg
Using the pressure forlmula;
P1 V1 = P2 V2
P1 A1 L1 = P2 A2 L2
where A1 and A2 is the area of the capillary tube and it is equal, it cancels out.
P1 l1 = P2 l2
l2 = P1 l1 / P2
l2 = 760 * 10 / 800
l2 = 9.5 cm
The length of the air in the tube is 9.5 cm.
Answer:
Explanation:
The glass rod losses electrons because the silk cloth has a positive charge so it attracts the negative charge of the glass rod.
<span>0.0687 m
The balanced equation is
BaCl2 + Na2SO4 ==> BaSO4 + 2 NaCl
Looking at the equation, it indicates that there's a 1 to 1 ratio of BaCl2 and Na2SO4 in the reaction. So the number of moles of each will be equal. Now calculate the number of moles of Na2SO4 we had. Start by looking up atomic weights.
Atomic weight sodium = 22.989769
Atomic weight sulfur = 32.065
Atomic weight oxygen = 15.999
Molar mass Na2SO4 = 2 * 22.989769 + 32.065 + 4 * 15.999 = 142.040538 g/mol
Moles Na2SO4 = 0.554 g / 142.040538 g/mol = 0.003900295 mol
Molarity is defined as moles per liter, so let's do the division.
0.003900295 mol / 0.0568 l = 0.068667165 mol/l = 0.068667165 m
Rounding to 3 significant figures gives 0.0687 m</span>
Answer : The rms speed of the molecules in a sample of gas at 300 K will be four times larger than the rms speed of molecules at the same temperature, and the ratio constant with increasing temperature.
Explanation :
Formula used for root mean square speed :
where,
= rms speed of the molecule
R = gas constant
T = temperature
M = molar mass of the gas
At constant temperature, the formula becomes,
And the formula for two gases will be,
Molar mass of = 32 g/mole
Molar mass of = 2 g/mole
Now put all the given values in the above formula, we get
Therefore, the rms speed of the molecules in a sample of gas at 300 K will be four times larger than the rms speed of molecules at the same temperature.
And the ratio constant with increasing temperature because rms speed depends only on the molar mass of the gases at same temperature.