Balanced equation is
HBr + NaOH ----> NaBr + H2O
Using molar masses
80.912 g HBr reacts with 39.997 g of Naoh to give 18.007 g water
so 1 gram of NaOH reacts with 2.023 g of HBR
and 5.7 reacts with 11.531 g HBr so we have excess HBr in this reaction
Mass of water produced = (5.7 * 18.007 / 39.997 = 2.6 g to 2 sig figs
The heat will flow from copper to aluminum because Cu is at higher temperature. The heat liberated is -7.60kJ
When two metals at different temperatures are kept in contact, heat flows from hotter metal to colder metal until thermal equilibrium is reached.
Here Copper is at a temperature of 60 degree Celsius and aluminum is at 40 degree Celsius. Thus, heat will flow from Cu to Al.
In order to calculate the amount of heat liberated following calculations are required.
m1=262 g
T1=87 oC
Cp=0.385 J/g oC
T2=11.8 oC
The heat liberated can be expressed as follows:
Q=mCp(T2-T1)
Q=262 g*0.385 J/goC(11.8-87)oC
Q=-7585 J
=-7.60kJ
To learn more about heat check the link below:
brainly.com/question/13439286
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Answer:
Explanation:
How many atoms are in a 3.5 g sample of sodium (Na)? In this example, multiply the grams of Na by the conversion factor 1 mol Na/ 22.98 g Na, with 22.98g being the molar mass of one mole of Na, which then allows cancelation of grams, leaving moles of Na.
