Answer:
0.302 moles
Explanation:
Data given
Mass of Pb(NO₃)₂ = 100 g
Moles of Pb(NO₃)₂ = ?
Solution:
To find mole we have to know about molar mass of Pb(NO₃)₂
So,
Molar mass of Pb(NO₃)₂ = 207 + 2[14 + 3(16)]
= 207 + 2[14 + 48]
= 207 + 124
Molar mass of Pb(NO₃)₂ = 331 g/mol
Formula used :
no. of moles = mass in grams / molar mass
Put values in above formula
no. of moles = 100 g / 331 g/mol
no. of moles = 0.302 moles
no. of moles of Pb(NO₃)₂ = 0.302 moles
The alkaline earth metals (the second group) because their ion charge is +2
Answer:
violet
Explanation:
Waves with a short wavelength have the most energy. Red waves have a relatively long wavelength (in the 700 nm range), and violet waves are much shorter - roughly half that. Because violet waves have the shortest wavelength of the visible light spectrum, they carry the most energy (google)
Answer:
Number of moles = 2.8 mol
Explanation:
Given data:
Number of moles of water = ?
Volume of water = 50 mL
Density of water = 1.00 g/cm³
Solution:
1 cm³ = 1 mL
Density = mass/ volume
1.00 g/mL = mass/ 50 mL
Mass = 1.00 g/mL× 50 mL
Mass = 50 g
Number of moles of water:
Number of moles = mass/molar mass
Number of moles = 50 g / 18 g/mol
Number of moles = 2.8 mol