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Steel wool , which is made of pure iron metal, burns with oxygen gas to produce ferric oxide (Fe2O3). Fe(s) + O2(g) ( Fe2O3
If there are 1.25 moles of Fe and 1.25 moles of O2,
How many moles of Fe2O3 will be produced? What is its mass?
If the actual laboratory yield is 95.8g Fe2O3, what is the rection’s percent yield?
Pure aluminum (Al) metal reacts with hydrocholoric acid (HCl) to produce aluminum chloride (AlCl3) and hydrogen (H2) gas.
Write the balanced chemical equation for the reaction described above.
If the expected mass of AlCl3 to be formed is 3.5g, what should be the initial mass of the pure aluminum metal?
If the actual mass of AlCl3 produced is 3.1g, what is the percentage yield of the reaction?
How many moles of O2 will be formed if 5.0 moles of H2O decomposed into H2 and O2?
Chemical Equation: H2O ( H2 + O2
How many moles of O2 are needed to burn 100 g of propane (C3H8)?
Chemcial Equation: C3H8 + O2 ( CO2 + H2O
If 50.0 grams of Cl2 gas is reacted with enough sodium hydroxide (NaOH), calculate the following:
Mass in grams of sodium hypochlorite (NaOCL) produced
Moles of sodium chloride (NaCl) produced
Chemical Equation: NaOH + Cl2 ( NaOCl + NaCl + H2O
Two ships A and B sail simultaneously from the same place. vessel A on course 300at 15 knots and B on course N 45°E at 10 knots. After 1 hour and 30 min, how far is vessel A to vessel B?
The examination results of a large group of students in Statistics are approximately normally distributed with a mean of 60 and a standard deviation of 9. If a student is chosen at random, what is the probability that his score is Below 45?
A trumpet creates a sound intensity level of 112 dB at a distance of 2.75 m. (a) What is the sound intensity of a trumpet at this distance. (b) What is the sound intensity of seven trumpets played simultaneously at this distance? (c) Calculate the sound intensity level of the seven trumpets played simultaneously at this distance.
2. A solution containing 0.402 49 g of CoCl2 ∙ xH2O (a solid with an unknown number of waters of hydration) was exhaustively electrolyzed to deposit 0.09937 g of metallic cobalt on a platinum cathode by the reaction Co2+ + 2e- Co(s). Calculate the number of moles of water per mole of cobalt in the reagent.
The average lifetime of 120 Brand X Alkaline AA batteries and 120 Brand Y alkaline AA batteries were found to be 9.1 hours and 9.6 hours respectively. Suppose the standard deviations of lifetimes are 1.9 for Brand X batteries and 2.1 hours for Brand Y batteries, test the hypothesis using α = 0.05
Tn=5n-4
An aptitude test for selecting officers in a bank was conducted on 1,000 candidates, the average score is 42 and the standard deviation of scores is 24. Assume that the scores are normally distributed, answer the following questions.
i. What is the probability that the candidates score,
A.Exceed 65?
B.Between 40 and 60?
ii. Find the number of candidates whose score,
A. Exceed 40?
B. Lie between 40 and 65?
An aptitude test for selecting officers in a bank was conducted on 1,000 candidates, the average score is 42 and the standard deviation of scores is 24. Assume that the scores are normally distributed, answer the following questions.
i. What is the probability that the candidates score,
A. Exceed 65?
B. Between 40 and 60?
ii. Find the number of candidates whose score,
A. Exceed 40?
B. Lie between 40 and 65?
#339914 on Dec 2023