Answer:
5.3 × 10⁻³ kg
Explanation:
There is some info missing. I think this is the original question.
<em>A chemist adds 135.0 mL of a 0.21 M zinc nitrate (Zn(NO₃)₂) solution to a reaction flask. Calculate the mass in kilograms of zinc nitrate the chemist has added to the flask. Be sure your answer has the correct number of significant digits.</em>
<em />
We have 135.0 mL of a 0.21 M zinc nitrate (Zn(NO₃)₂) solution. The moles of zinc nitrate are:
0.1350 L × 0.21 mol/L = 2.8 × 10⁻² mol
The molar mass of zinc nitrate is 189.36 g/mol. The mass corresponding to 2.8 × 10⁻² moles is:
2.8 × 10⁻² mol × 189.36 g/mol = 5.3 g
1 kilogram is equal to 1000 grams. Then,
5.3 g × (1 kg/1000 g) = 5.3 × 10⁻³ kg
I think the correct answer from the choices listed above is option A. It is the salt bridge that balances charges that may build up as reduction and oxidation occur in a voltaic cell. The salt bridge is to <span>maintain charge balance because the electrons are moving from one half cell to the other.</span>
Answer : The mass of helium added to the cylinder was, 1.5 grams
Explanation :
Avogadro's law : It is defined as the volume of gas is directly proportional to the number of moles of gas at constant pressure and temperature.
or,
where,
= initial volume of gas = 2.00 L
= final volume of gas = 3.50 L
= initial moles of gas = 
= final temperature of gas = ?
Now put all the given values in the above equation, we get:
Now we have to calculate the mass of helium were added to the cylinder.
Mass of helium added = 3.5 - 2.00 = 1.5 g
Thus, the mass of helium added to the cylinder was, 1.5 grams
Kinda blurry can’t see it
<h2>Answer:</h2>
<u>In order to measure the zone of inhibition we measure the diameter of the zone of inhibition including the diameter of the disc.</u>
<h2>Explanation:</h2>
A Zone of Inhibition Test, also called a Kirby-Bauer Test, is a qualitative method used clinically to measure antibiotic resistance and industrially to test the ability of solids and textiles to inhibit microbial growth. The zone is measured by the diameter across the zone and you do not consider the disc at all. Zone is measured from edge to edge of the clear area , which means disc will be inside and included in the measurement.
