Take note of the subscript written for each element in the compound. To find the total number of moles, make sure to multiply the subscript with the number of moles of compound. The answer for each is written below:
a. 3*1 = 3 moles Nitrogen; 3*3 = 9 moles Hydrogen
b. 0.25*2 = 0.5 moles Hydrogen; 0.25*1 = 0.25 moles Oxygen
c. 5*2 = 10 moles Hydrogen; 5*1 =5 moles Sulfur; 5*4 = 20 moles Oxygen
d. 0.75*1 = 0.75 moles Calcium; 0.75*1*2 = 1.5 moles Nitrogen; 0.75*3*2 = 4.5 moles Oxygen
Answer:
M = 0.138 M
Explanation:
Given data:
Mass of glucose = 12.55 g
Volume of solution = 500 mL
Molarity of solution = ?
Solution:
Molarity is used to describe the concentration of solution. It tells how many moles are dissolve in per litter of solution.
Formula:
Molarity = number of moles of solute / L of solution
Number of moles of glucose:
Number of moles = mass/molar mass
Number of moles = 12.55 g/ 180.156 g/mol
Number of moles = 0.069 mol
Volume in L:
500 mL × 1 L /1000 mL
0.5 L
Molarity:
M = 0.069 mol / 0.5 L
M = 0.138 M
Answer:
0.164541341 g H2
Explanation:
1) Convert grams to moles by dividing by RMM of Magnesium (24.31g).
2g Mg * (1 mol Mg / 24.31 g Mg) = 0.082270671 mol of Mg
2) Use the balanced equation's ratio of 1 mol Mg: 1 mol H2.
0.082270671 mol of Mg = 0.082270671 mol of H2
3) Convert the mol of H2 back into grams by multiplying by H2's RMM (2 g).
0.082270671 mol of H2 * 2 g H2 = 0.164541341 g H2
* Answer can be rounded to your liking *
Al +3CuCl--->AlCl3+3Cu , its balanced equation
Given that the mass of coffee in the cup = 140 g
Final temperature = 
Initial temperature = 
Let us assume the specific heat of coffee is equal to that of water = 4.184
Temperature change = T(final) - T(initial) = (20 - 75 )
=- 55
-Heat given out by coffee = heat absorbed by the surroundings
Heat released into the surroundings =-(
)
= 
= 32,217 J
