Answer:
Endothermic
Explanation:
The temperature of the water decreased.
The water lost heat.
The heat must have gone into getting the KNO₃ into solution.
So, the dissolving of KNO₃ in water is endothermic.
Answer:
0.171 M
Explanation:
Step 1: Given data
- Mass of H₃PO₄ (solute): 3.35 g
- Volume of solution (V): 200 mL
Step 2: Calculate the moles of solute
The molar mass of H₃PO₄ is 97.99 g/mol.
3.35 g × 1 mol/97.99 g = 0.0342 mol
Step 3: Convert "V" to liters
We will use the conversion factor 1 L = 1000 mL.
200 mL × 1 L/1000 mL = 0.200 L
Step 4: Calculate the molarity of the solution
We will use the definition of molarity.
M = moles of solute / liters of solution
M = 0.0342 mol/0.200 L = 0.171 M
Answer:
606 atoms
Explanation:
Add the numbers 145 + 293 + 168
P1v1/t1 = p2t2/t2
p is constant
v1=600, t1 =20c=293K
v2=?, t2=60c=333K
temperature must be in Kelvin
do the math
