False - A producer always provides food for the consumer.
Answer:
2.21 x 10⁻⁷m⁻¹
Explanation:
Given parameters:
Energy of the photon = 9.02 x 10⁻¹⁹J
Unknown:
Wavelength of the photon = ?
Solution;
The wavelength and energy of a photon are related using the expression below;
E = 
h is the Planck's constant = 6.63 x 10⁻⁴m²kg/s²
c is the speed of light
E is the energy
h c = E x wavelength
Wavelength = 
= 
Wavelength = 2.21 x 10⁻⁷m⁻¹
4. Elements in the same group on the periodic table have the same number of valence electrons.
5. Properties of elements within a period on the periodic table change in a predictable way from one side of the table to the other.
6. The number of protons in an atom determines the identity of the element.
Answer:
Percent yield = 57%
Explanation:
Given data:
Mass of nitrogen = 15.0 g
Mass of hydrogen = 15.0 g
Mass of ammonia produced = 10.5 g
Percent yield = ?
Solution:
Chemical equation:
N₂+ 3H₂ → 2NH₃
Number of moles of hydrogen:
Number of moles = mass/molar mass
Number of moles = 15.0 g/ 2 g/mol
Number of moles = 7.5 mol
Number of moles of nitrogen:
Number of moles = mass/molar mass
Number of moles = 15.0 g/ 28 g/mol
Number of moles = 0.54 mol
Now we will compare the moles of ammonia with nitrogen and hydrogen from balance chemical equation.
N₂ : NH₃
1 : 2
0.54 : 2×0.54 = 1.08
H₂ : NH₃
3 : 2
7.5 : 2/3×7.5= 5 mol
Theoretical yield of ammonia:
Mass = number of moles × molar mass
Mass = 1.08 × 17 g/mol
Mass = 18.36 g
Percent yield:
Percent yield = (actual yield / theoretical yield) ×100
Percent yield = (10.5 g/ 18.36 g) ×100
Percent yield = 0.57 ×100
Percent yield = 57%
Answer:
2,981g
Explanation:
Firstly, we need to find the number of moles of MgCl that we have by using the formula: mass = No. Moles x Molar Mass, which we can rearrange so that we are solving for no. moles:
No. Moles = mass / Molar Mass
We are given a mass of 621g, and we can calculate the molar mass of MgCl by adding the two molar masses together: 24.31+35.45 = 59.76
Now we can calculate number of moles by substituting these values into the formula:
n = 621 / 59.76
No. moles = 10.4
Now we can use the co-efficients in the formula to tell us how many moles of AgCl will be formed. The coefficient of MgCl is 1, and the coefficient of AgCl is 2. This means that every 1 mol of MgCl will form 2 moles of AgCl. So, to find the no. moles of AgCl, we multiply our no. moles by 2:
10.4 x 2 = 20.8 moles
Finally we convert this back into mass by multiplying the no. moles by the Molar mass of AgCl:
m = 20.8 x (107.87+35.45)
m = 2,981g
