Answer:
A
Explanation:
if the earth slows down then that will give more time to the sun meaning days/nights will be longer
The concentration of the original calcium ions is 0.005 M
<h3>What is concentration?</h3>
The term concentration has to do with the amount of substance in solution. We know that the concentration can be measured in a lot of units such as mole/litre, grams per litre, percentage and so on.
As such we have the equation;
Ca^2+(aq) + (NH4)2CrO4(aq) --------> CaCrO4(s) + 2NH4^+(aq)
Number of moles of the precipitate = 346.7 * 10^-3 g/156 g/mol
= 0.0022 moles
Now;
1 mole of Ca^2+ produces 1 mole of CaCrO4 hence 0.0022 moles of CaCrO4 was produced by 0.0022 moles of CaCrO4.
Given that the volume of the solution is 0.440 L, the concentration of the solution is; 0.0022 moles/0.440 L
= 0.005 M
Learn more about molarity:brainly.com/question/8732513
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<span>The student should
follow following steps to make 1 L of </span>2.0 M CaCl₂.<span>
<span>
1. First he should
calculate the number of moles of 2.0 M CaCl</span></span>₂ in 1 L solution.<span>
</span>Molarity of the solution = 2.0 M<span>
Volume of solution which should be prepared = 1 L
Molarity =
number of moles / volume of the solution
Hence, number of moles in 1 L = 2 mol
2. Find
out the mass of dry CaCl</span>₂ in 2 moles.<span>
moles =
mass / molar mass
Moles of CaCl₂ =
2 mol</span><span>
Molar mass of CaCl₂ = </span><span>110.98 g/mol
Hence, mass of CaCl</span>₂ = 2 mol x <span>110.98 g/mol
= 221.96
g
3. Weigh the mass
accurately
4. Then take a cleaned and dry1 L volumetric flask and place a funnel top of it. Then carefully add the salt into the volumetric flask and
finally wash the funnel and watch glass
with de-ionized water. That water also should be added into the volumetric
flask.
5. Then add some
de-ionized water into
the volumetric flask and swirl well until all salt are
dissolved.
<span>6. Then top up to
mark of the volumetric flask carefully.
</span></span>
7. As the final step prepared solution should be labelled.
Answer:
mxmxmxmxmxmxmxnxnsjjsjsjsjs
kskskw
Explanation:
msmsjsjdjdj
make
wokskwkwkwkwjjejesjsjjsjwjwj
Answer:
the original answer is 38.9km (3sf)
