Answer:
3.69 g
Explanation:
Given that:
The mass m = 325 g
The change in temperature ΔT = ( 1540 - 165)° C
= 1375 ° C
Heat capacity 
= 0.490 J/g°C
The amount of heat required:
q = mcΔT
q = 325 × 0.490 × 1375
q = 218968.75 J
q = 218.97 kJ
The equation for the reaction is expressed as:
Then,
1 mole of the ethyne is equal to 26 g of ethyne required for 1544 kJ heat.
Thus, for 218.97 kJ, the amount of ethyne gas required will be:
= 3.69 g
Answer:
A. 0.0655 mol/L.
B. PbBr2.
C. Pb2+(aq) + Br- --> PbBr2(s).
Explanation:
Balanced equation of the reaction:
Pb(NO3)2(aq) + 2NaBr(aq) --> PbBr2(s) + 2NaNO3(aq)
A.
Number of moles
PbBr2
Molar mass = 207 + (80*2)
= 367 g/mol.
Moles = mass/molar mass
= 3.006/367
= 0.00819 mol.
Since 2 moles of NaBr reacted to form 1 mole of PbBr2. Therefore, moles of NaBr = 2*0.00819
= 0.01638 moles of NaBr.
Since, the ionic equation is
NaBr(aq) --> Na+(aq) + Br-(aq)
Since 1 moles of NaBr dissociation in solution to give 1 mole of Br-
Therefore, molar concentration of Br-
= 0.0164/0.25 L
= 0.0655 mol/L.
B.
PbBr2
C.
Pb(NO3)2(aq)--> Pb2+(aq) + 2No3^2-(aq)
2NaBr(aq) --> 2Na+(aq) + 2Br-(aq)
Net ionic equation:
Pb2+(aq) + 2Br- --> PbBr2(s)
As you go across a period, radius shrinks because you are adding protons. The added positive charge increases pull on the electron shells.
As you go down a group, radius gets larger because you are increasing shells of electrons. This increases shielding of the nucleus' positive charge, so the electrons are not pulled in as much.
Need more context maybe put a picture or explain a little more
Answer:
When iron turns to rust, the chemical identity of the iron changes. When you break ice, the ice is still ice
