1.39 g HCl
Explanation:
The balanced chemical equation for this reaction is given by
Zn(<em>s</em>) + 2HCl(<em>aq</em>) ---> ZnCl2(<em>aq</em>) + H2(<em>g</em>)
Convert the # of grams of Zn to moles:
1.25 g Zn × (1 mol Zn/65.38 g Zn) = 0.0191 mol Zn
Use the molar ratio to find the # of moles of HCl needed to react completely with the given amount of Zn:
0.0191 mol Zn × (2 mol HCl/1 mol Zn) = 0.0382 mol HCl
Convert this amount to grams:
0.0382 mol HCl × (36.458 g HCl/1 mol HCl) = 1.39 g HCl
Answer:
i need a picture or more info to understand
Answer:
67.6 years is the time the isotope take to decay from 0.900g to 0.170g
Explanation:
The radioactive decay follows first order law:
Ln [A] = -kt + ln[A]₀
<em>Where [A] is concentration after time t,</em>
<em>k is decay constant:</em>
<em>k = ln 2 / t(1/2)</em>
<em>k = ln2 / 28.1 years</em>
<em>k = 0.02467 years⁻¹</em>
<em>[A]₀ = Initial concentration.</em>
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We can replace concentration and use the mass of the isotope:
Ln [A] = -kt + ln[A]₀
Ln [0.170g] = -0.02467 years⁻¹t + ln[0.900g]
-1.667 = -0.02467 years⁻¹t
t =
<h3>67.6 years is the time the isotope take to decay from 0.900g to 0.170g</h3>
Answer:
1.d = 2.70 g/mL
2.d = 13.6 g/mL
4.d = 1896 g / 212.52 cm3 = 8.9 g/cm3
Explanation:If this helped subscribe to Amiredagoat Yt
Answer:
In 4 years the carbon monoxide level reach 7.8 parts per million.
Explanation:
The average daily level of carbon monoxide in the air is given by :
parts per million..[1]
The population of the region after t years is modeled by the formula :
...[2]
If level of carbon monoxide level reach 7.8 parts per million in t years.
Using [1] to calculate value of x.
c(x)= 7.8 parts per million
c(x) = 0.5x + 2 parts per million
7.8 parts per million = (0.5x + 2 ) parts per million
Solving for x , we get ;
x = 11.6
Using [2] to calculate value of t.:
x(t) = 11.6
Solving for 't' we get ;
t = 4 years
In 4 years the carbon monoxide level reach 7.8 parts per million.
