The moles of hydrogen which are produced from 57.5 grams of lithium is 8.21 grams.
<h3>What is stoichiometry?</h3>
Stoichiometry of the reaction gives idea about the relative amount of product produced by the reactant in terms of moles.
Given chemical reaction is:
2Li(s) + H₂O(l) → 2LiOH(aq) + H₂(g)
Moles of lithium will be calculated as:
n = W/M, where
- W = given mass = 57.5g
- M = molar mass = 7g/mol
n = 57.5 / 7 = 8.21 mol
From the stoichiometry of the reaction:
- 2 moles of Li = produces 1 mole of H₂
- 8.21 moles of Li = produces 8.21/2=4.105 moles of H₂
Mass of H₂ = (4.105mol)(2g/mol) = 8.21g
Hence required mass of hydrogen gas is 8.21g.
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Answer:
All of the above. The CV system transports blood and plasma the do all 4.
Answer:
Density, 
Explanation:
It is given that, placing a sample of iron (II) oxide into a graduated cylinder makes the water volume increase 12.0 mL.
It means that the volume of the sample is 12 mL
The weight of the sample is 76.6 g
We need to find the density of the sample.
12 mL = 12 cm³
The formula of density is given by :
So, the density of the sample is 
.
Whats your question here?
Assuming a basis of 100 g of Kevlar, therefore the masses
are:
C = 70.6 g
H = 4.2 g
N = 11.8 g
O = 13.4 g
We know the molar masses are:
C = 12.01, H = 1.008, N = 14.01, O = 16.00
Calculating for the moles per element:
C = 70.6 / 12.01 = 5.88 mol
H = 4.2 / 1.008 = 4.17 mol
N = 11.8 / 14.01 = 0.84 mol
O = 13.4 / 16 = 0.84 mol
To get the empirical formula, the next step is to divide
everything by the smallest moles = 0.84. So:
C = 7
H = 5
N = 1
O = 1
Hence the empirical formula is:
C7H5NO
