Answer:
0.09375M
Explanation:
There are two methods of going about this, either we use dilution formula (easiest and fastest) or we solve through molarity.
Using dilution formula,
C2 (H2SO4) = ?
C1 (NaOH) = 0.25M
V2 (H2SO4) = 20cm³
V1 (NaOH) = 15cm³
However we can solve using molarity method
Equation of reaction =
2NaOH + H2SO4 ====》 Na2SO4 + 2H2O
O.25M of NaOH = 1000cm³
X moles = 15cm³
X = (0.25 * 15) / 1000
X = 0.00375 moles is present in 15cm³ of NaOH
From equation of reaction,
2 moles of NaOH requires 1 mole of H2SO4
Therefore
0.00375 / 2 = 0.001875 moles is present in H2SO4
From the reaction,
0.00187 moles of H2SO4 = 20 cm³
X moles = 1000cm³
X = (0.00187*1000) / 20 = 0.09375M
The total number of matchbooks required would 5,000 be and the cost would be $144
<h3>Mathematical ratios</h3>
50 matchbooks = $1.44
Each matchbook = 0.005 grams red phosphorus
25 grams of red phosphorus is needed:
25/0.005 = 5,000 matchbooks
5,000 matchbooks will cost:
5000/50 x 1.44 = $144
More on mathematical ratios can be found here: brainly.com/question/20387079
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a) 
→ 
b) 
→ 
<h3>
What are half-reactions?</h3>
The half-reaction method is a way to balance redox reactions. It involves breaking the overall equation down into an oxidation part and a reduction part.
a)
→
= 
= -0.83 - (-2.71) =1.88V
b)
→
= 
=-0. - (0.8) =-0.8V
Learn more about the half-reactions here:
https://brainly.in/question/18053421
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4 mol / 205g H2O = 4/.205 = 19.5 mol/kg boiling point = 100 + 19.5 • 0.51 = 109 ºC
Answer:
1 g
Explanation:
Given data:
Volume of solution = 250 mL (250 mL × 1 L/1000 mL = 0.25 L)
Molarity of solution = 0.1 M
Amount of sodium hydroxide = ?
Solution:
Molarity = number of moles / volume in L
0.1 M = number of moles /0.25 L
Number of moles = 0.1 M × 0.25 L
M = mol/ L
Number of moles = 0.025 mol
Mass of sodium hydroxide:
Mass = number of moles × molar mass
Mass = 0.025 mol ×40 g/mol
Mass = 1 g
