Answer:- 0.800 moles of the gas were collected.
Solution:- Volume, temperature and pressure is given for the gas and asks to calculate the moles of the gas.
It is an ideal gas law based problem. Ideal gas law equation is used to solve this. The equation is:
PV=nRT
Since it asks to calculate the moles that is n, so let's rearrange this for n:

V = 19.4 L
T = 17 + 273 = 290 K
P = 746 mmHg
we need to convert the pressure from mmHg to atm and for this we divide by 760 since, 1 atm = 760 mmHg

P = 0.982 atm
R = 
Let's plug in the values in the equation to get the moles.

n = 0.800 moles
So, 0.800 moles of the gas were collected.
Answer:
0.17325 moles per liter per second
Explanation:
For a first order reaction;
in[A] = in[A]o - kt
Where;
[A]= concentration at time t
[A]o = initial concentration
k= rate constant
t= time taken
ln0.5 =ln1 - 2k
2k = ln1 - ln0.5
k= ln1 - ln0.5/2
k= 0 -(0.693)/2
k= 0.693/2
k= 0.3465 s-1
Rate of reaction = k[A]
Rate = 0.3465 s-1 × 0.50 mol/L
Rate = 0.17325 moles per liter per second
Answer:

Explanation:
Hello there!
In this case, it is possible to comprehend these mass-particles problems by means of the concept of mole, molar mass and the Avogadro's number because one mole of any substance has 6.022x10²³ particles and have a mass equal to the molar mass.
In such a way, for C₆H₁₂O₆, whose molar mass is about 180.16 g/mol, the referred mass would be:

Best regards!
Answer:
iron (III) oxide is a gas
Answer:
B. People live longer than they used to
Explanation:
None of the other answers are correct.