Answer:
i)a. P & R
b. Q& S
ii) R
iii) Atomic no & Atomic radius
2)a. C4H10
b. CH3Cl
A double-edged stainless steel can float on water. Without surface tension, the blade would sink because its weight is greater than its buoyant surface.
Answer: The blade doesn't sink because of the surface tension of the water.
Answer:
12.5 g
Explanation:
If element R's half life is 2 minutes then we need to divide 100 g by 1/2 3 times. 100/2 = 50/2= 25/2= 12.5 g.
Hope this helps!
<h3>
Answer:</h3>
318.405 g
<h3>
Explanation:</h3>
We are given;
- Volume of K₃PO₄ solution to be prepared as 750.0 mL or 0.75 L
- Molarity of the solution to be prepared as 2.00 M
We are required to determine the mass of K₃PO₄ to be measured.
<h3>Step 1: Determine the number of moles of K₃PO₄</h3>
Molarity = Moles ÷ Volume
Rearranging the formula;
Number of moles = Molarity × Volume
Therefore;
Moles of K₃PO₄ = 2.00 M × 0.75 L
= 1.5 moles
<h3>Step 2: Determine the mass of K₃PO₄ to be measured</h3>
Mass = Number of moles × Molar mass
Molar mass of K₃PO₄ = 212.27 g/mol
Therefore;
Mass of K₃PO₄ = 1.5 moles × 212.27 g/mol
= 318.405 g
Therefore, the mass of K₃PO₄ that should be weighed is 318.405 g
Answer: Glassware C
Explanation:
According to moalrity equation:

= Molarity of stock solution = 4.50 M
= volume of stock solution = ?
= molaity of diluted solution = 1.35 M
= volume of diluted solution = 250.0 ml


A volumetric flask is more accurate for making solutions than a beaker or erlenmeyer flask and hence to measure 75.0 ml of stock solution , we use 250 ml of volumetric flask.
Thus 75.0 ml of stock is pipetted out using pipette and put into a volumetric flask of 250 ml and water is added till the mark reaches 250 ml.
A volumetric flask is more accurate for making solutions than a beaker or erlenmeyer flask and hence to measure 75.0 ml of stock solution , we use 250 ml of volumetric flask.