Answer: The molar enthalpy change is 73.04 kJ/mol
Explanation:

moles of HCl= 
As NaOH is in excess 0.0415 moles of HCl reacts with 0.0415 moles of NaOH.
volume of water = 100.0 ml + 50.0 ml = 150.0 ml
density of water = 1.0 g/ml
mass of water = 

q = heat released
m = mass = 150.0 g
c = specific heat = 
= change in temperature = 


Thus 0.0415 mol of HCl produces heat = 3031.3 J
1 mol of HCL produces heat = 
Thus molar enthalpy change is 73.04 kJ/mol
Answer:
3.79 x 10²⁴atoms
Explanation:
Given parameters:
Number moles of lead = 6.3moles
Unknown:
Number of atoms = ?
Solution:
To solve this problem,
1 mole of a substance contains 6.02 x 10²³ atoms
6.3 mole of Pb will contain 6.3 x 6.02 x 10²³ = 3.79 x 10²⁴atoms
When a neutral hydrogen atom loses an electron, a positively-charged particle should remain.
Volume is an extensive property of a marker ink and color is an intensive property of a marker ink.
Answer: 483 mL of the cleaning solution are used to clean hospital equipment
Explanation:
The question requires us to calculate the volume, in mL, of solution is used to clean hospital equipment, given that 415g of this solution are used and the specific gravity of the solution is 0.860.
Measurements > Density
Specific gravity is defined as the ratio between the density of a given substance to the density of a reference material, such as water:

The density of a substance is defined as the ratio between the mass and the volume of this substance:

Considering the reference substance as water and its density as 1.00 g/mL, we can determine the density of the substance which specific gravity is 0.860:

Thus, taking water as the reference substance, we can say that the density of the cleaning solution is 0.860 g/mL.
Now that we know the density of the cleaning solution (0.860 g/mL) and the mass of solution that is used to clean hospital equipment (415g), we can calculate the volume of solution that is used to clean the equipment:

Therefore, 483 mL of the cleaning solution are used to clean hospital equipment.