Answer:
<em><u>0.27 g</u></em>
Explanation:
The reaction equation:
→
106g of Na2CO3 - 1 mole
0.5g of Na2CO3 = 0.5 ÷ 106
= 0.0047 moles.
1 mole of NaCl - 58.5
⇒ 0.0047 moles = 0.0047 × 58.5
= 0.27g.
Answer:
c.I ,II & IV are correct
Explanation:
Phenolphthalein is an indicator. An indicator is an organic dye whose solution changes colour as the concentration of hydrogen ions in solution changes.
Hence a typical indicator exhibits different colours at different pH ranges. The colour of an indicator in an acid, a base and at end point always differs.
Phenolphthalein is a colourless solution which has a pink colour in an alkaline medium and colourless in an acidic medium.
ΔG > 0
is always true for the freezing of water.
Explanation:
- The freezing of water is only spontaneous when the temperature is fairly small. Over 273 K, the higher value of TΔS causes the sign of ΔG to be positive, and there is no freezing point.
- The entropy decreases as water freezes. This does not infringe the Thermodynamics second law. The second law doesn't suggest entropy will never diminish anywhere.
- Entropy will decline elsewhere, provided it increases by at least as much elsewhere.
Answer: 2.78 L
Explanation:
Given that,
Original volume V1 = 1.2 L
Original pressure P1 = 5.1 kPa
New pressure P2 = 2.2 kPa
New volume V2 = ?
Since pressure and volume are given while temperature is constant, apply the formula for Boyle's law
P1V1 = P2V2
5.1 kPa x 1.2L = 2.2 kPa x V2
6.12 kPa L = 2.2 kPa x V2
V2 = 6.12 kPa L / 2.2L
V2 = 2.78 L
Thus, the new volume of the gas would be 2.78 Liters