I think the answer most be d
Hey there!
Molar mass Na2SO4 = <span>142.04 g/mol
Number of moles:
n = m / mm
n = 25 / 142.04
n = 0.176 moles of Na2SO4
Therefore, </span>use the Avogadro constant
1 mole Na2SO4 ------------------- 6.02x10²³ molecules
0.176 moles Na2SO4 ------------ molecules ??
0.176 x ( 6.02x10²³ ) / 1
=> 1.059x10²³ molecules of Na2SO4
hope this helps!
Hey there!
NaHCO₃
Notice that there is no subscript under Na.
That means there is one atom of Na for each molecule of NaHCO₃.
Hope this helps!
I think it’s the constants
Answer:
Explanation:
Utilizing Rydber's equation:
ΔE = Z²Rh ( 1/n₁² - 1/n₂²) and substituting the values given ( using the Rydbers constant value in Joules ), we have
n=1 to n= infinity
ΔE = 3² x (1/1² - 0) x 2.18 x 10⁻^18 J = 2.0 x 10⁻¹⁷ J (1/infinity is zero)
n= 3 to n= infinity
ΔE = 3² x (1/3² - 0) x 2.18 x 10⁻^18 J = 2.28 x 10^-18 J
b. The wavelength of the emitted can be obtained again by using Rydberg's equation but this time use the constant value 1.097 x 10⁷ m⁻¹ given in the problem .
1/λ = Z²Rh (1/n₁² - 1/n₂²) 10 ⁻¹ = 3² x 1.097 x 10⁷ m⁻¹ x (1/1² - 1/3²) m⁻¹
1/λ =8.8 x 10⁷ m⁻¹ ⇒ λ =1.1 x 10^-8 m
λ = 1.1 x 10^-8 m x 1 x 10⁹ nm/m = 11 nm
