I need help with this please (sorry the picture is blurry.)
1 answer:
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Answer:
- 0.71963 g of Zn
- 0.80256 g of HCl
Step-by-step explanation:
The required mass of reactants can be computed from the number of moles of product.
moles of ZnCl₂ = (1.5 g)/(136.282 g) ≈ 0.0110066 moles
Then the mass of Zn required is ...
mass of Zn = (0.0110066 mol)(65.382 g/mol) = 0.71963 g
Two moles of HCl are used in the reaction with each mole of Zn, so the mass of HCl required is ...
mass of HCl = 2(0.0110066 mol)(36.458 g/mol) = 0.80256 g
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<em>Comment</em>
The discrepancy in the last two decimal places of the weights above versus the calculator output below comes from rounding of moles of Zn to 4 significant digits, instead of 5 or more. The number of moles of ZnCl₂ is closer to 0.0110066.
Answer:
If we define the random variable X ="time spend by the students doign homework"
And we want to tes t is students spend more than 1 hour doing homework per night, on average (alternative hypothesis), so then the system of hypothesis for this case are:
Null hypothesis:
Alternative hypothesis:
And they wnat to use a sample size of n = 100 and a significance level of 0.05
Step-by-step explanation:
Previous concepts
A hypothesis is defined as "a speculation or theory based on insufficient evidence that lends itself to further testing and experimentation. With further testing, a hypothesis can usually be proven true or false".
The null hypothesis is defined as "a hypothesis that says there is no statistical significance between the two variables in the hypothesis. It is the hypothesis that the researcher is trying to disprove".
The alternative hypothesis is "just the inverse, or opposite, of the null hypothesis. It is the hypothesis that researcher is trying to prove".
Solution to the problem
If we define the random variable X ="time spend by the students doign homework"
And we want to tes t is students spend more than 1 hour doing homework per night, on average (alternative hypothesis), so then the system of hypothesis for this case are:
Null hypothesis:
Alternative hypothesis:
And they wnat to use a sample size of n = 100 and a significance level of 0.05