Answer:
Molar mass Na2CO3 = 2*23 + 12 + 3*16 = 106 g/ mol
Mass of 1 mol Na2CO3 = 106 g
mass (Na2CO3) = 106g*250cm³/1000cm³ = 26.5 g
1) It is necessary because all Na2CO3 will be in the solution, and no Na2CO3 would be lost.
2) Because the solution that was formed after rinsing beaker contains Na2CO3.
3) Eyes should be on the level of calibration mark of the volumetric flask.
4) It is necessary to prevent evaporation of water, and changing , because of it, the concentration of the solution.
Answer:
No because it changes velocity, instead of accelerating
Explanation:
and yes, I am in K12 ツ
Answer:
7.34684 × 10^23 atoms
Explanation:
Well, one mole is basically
6.022 × 10^23 atoms. So 1.22 moles would be
6.022 × 10^23 ⋅ 1.22 atoms.
6.022 × 10^23 ⋅ 1.22 = 7.34684 × 10^23 atoms
Answer:
60.12 miles
Explanation:
Using the calculation formula shown below:
![t_{1/2} =\frac{t}{[tex]log_{2}](https://tex.z-dn.net/?f=t_%7B1%2F2%7D%20%3D%5Cfrac%7Bt%7D%7B%5Btex%5Dlog_%7B2%7D)
\frac{N_{o} }{N_{t} } }[/tex]
where:
is the half life, 
is the original amount of F-18, and 
is the remaining amount of F-18 at time t.
Generally, F-18 has an half life of 1.83 hours.
Therefore:
![t = 1.83*[tex]log_{2}](https://tex.z-dn.net/?f=t%20%3D%201.83%2A%5Btex%5Dlog_%7B2%7D)
\frac{100}{68} = 1.02 hours[/tex]
Therefore using a speed of 59 miles/hour, the closeness of the hospital is:
distance = speed*time = 59*1.02 = 60.12 miles
