Did I do everything right?

How scientists used the scientific method to learn more about how dinosaurs became extinct

lesya [120]

Answer:

they tested the bone age

Explanation:

4 0

2 years ago

True or False? The fatal 1930 incident in Muese Valley, Belgium, was associated with leakage of toxic chemicals from a former du

Westkost [7]

Answer:

FALSE

Explanation:

The incident of Muese Valley occured in 1930 due to air pollution.

Muese Valley lies along the river Muese which is situated Huy and Liege, Belgium. This region was crowded with industries including steel manufacturers, glass manufacturers, explosives plants, zinc smelter, etc.

The increase number of industries and population lead to the sources of pollution. Also increase in burning of domestic coal increased pollution surrounding the area.

Air pollution became so severe at this region that people have severe respiratory problems. Residents suffered from vomiting, retrosternal pain, coughing fits and several experienced nausea. There were fog and smog all over and many people died.

Hence the answer is FALSE.

8 0

2 years ago

What volume is occupied by 18.4 g oxygen at 28.0°C and a pressure of 0.998 torr? (round to sig figs)

Alexxandr [17]

Answer:

11.0 dm³

Explanation:

From the question,

Applying

PV= nRT............... Equation 1

Where P = pressure of oxygen gas, V = volume of oxygen gas, n = number of moles of oxygen, R = molar constant, T = Temperature.

make V the subeject of the equation

V = nRT/P............. Equation 2

But,

Number of mole (n) = Mass of oxygen(m)/Molar mass of oxygen(m')

n = m/m'....................... Equation 3

Substitute equation 3 into equation 2

V = mRT/Pm'............. Equation 4

Given: T = 28°C = (28+273) = 301 K, P = 0.998 torr = (0.998×0.00131579) = 1.3132 atm, m = 18.4 g

Constant: R = 0.082 atm.dm³/K.mol, m' = 32 g/mol.

Substitute these values into equation 4

V = (301×18.4×0.082)/(32×1.3132)

V = 454.1488/42.0224

V = 10.81 dm³

V = 11.0 dm³

8 0

2 years ago

What is the final volume of 20L of gas at 300K that is heated to 600K at constant pressure?

maxonik [38]

Answer:

40

Explanation:

6 0

2 years ago

Calculate hydrochloric acid (umol)in 200 ul of a 0.5173Msolution of acid?

strojnjashka [21]

Answer: The moles of hydrochloric acid is $1.0346\times 10^{-4}\mu mol$

Explanation:

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

$\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}$

Or,

$\text{Molarity of the solution}=\frac{\text{Micro moles of solute}\times 10^6}{\text{Volume of solution (in }\mu L)}}$

We are given:

Molarity of solution = 0.5173 M

Volume of solution = $200\mu L$

Putting values in above equation, we get:

$0.5173M=\frac{\text{Micro moles of HCl}\times 10^6}{200\mu L}\\\\\text{Micro moles of HCl}=1.0346\times 10^{-4}\mu mol$

Hence, the moles of hydrochloric acid is $1.0346\times 10^{-4}\mu mol$

7 0

2 years ago