<u>Answer:</u> The density of liquid is 
<u>Explanation:</u>
We are given:
Mass of cylinder,
= 65.1 g
Mass of liquid and cylinder combined, M = 120.5 g
Mass of liquid,
= 
To calculate density of a substance, we use the equation:

We are given:
Mass of liquid = 55.4 g
Volume of liquid = 49.3 mL =
(Conversion factor:
)
Putting values in above equation, we get:

Hence, the density of liquid is 
Answer:
when CO2 gas is passed through lime water it turns milky due to the formation of calcium carbonate which formula is CaCO3.
Ca(OH)2+ CO2------ CaCO3
when excess of carbon dioxide is passed through calcium carbonate calcium hydrogen carbonate is formed and solution become colourless.
CaCO3+CO2------ Ca(HCO3)
Answer: A different group of scientists using different methods.
Molar mass :
NaBr = 103 g/mol
Pb(NO3)2 = 331.20 g/mol
<span><span /><span>Balanced chemical equation :
</span></span>2 NaBr + 1 Pb(NO3)2 = 2 NaNO3 + 1 PbBr<span>2
</span><span>
2*103 g NaBr ------------> 1 * 331.20 g Pb(NO3)2
g NaBr -------------------> 311 g Pb(NO3)2
331.20 g = 2*103*311
331.20 g = 64066
mass ( NaBr ) = 64066 / 331.20
mass ( naBr) = 193,43 g of NaBr
hope this helps!.
</span>