Given:3.40g sample of the steel used to produce 250.0 mLSolution containing Cr2O72−
Assuming all the Cr is contained in the BaCrO4 at the end.
(0.145 g BaCrO4) / (253.3216 g BaCrO4/mol) x (250.0 mL / 10.0 mL) x (1 mol Cr / 1 mol BaCrO4) x (51.99616 g Cr/mol / (3.40 g) = 0.219 = 21.9% Cr
Answer:
The sun's circumference is about 2,713,406 miles (4,366,813 km). It may be the biggest thing in this neighborhood, but the sun is just average compared to other stars. Betelgeuse, a red giant, is about 700 times bigger than the sun and about 14,000 times brighter.
Explanation:
looked it up
Their lungs would try to expand to about 4 timed the normal volume which would force air into the various body tissues. this can cause a lung expansion injury and it could case air embolism. Air embolism is when air bubbles get trapped in blood vessels. This can lead to a blockage which will could be fatal.
Answer:
A chemical change
Explanation:
The marshmallow turning brown and bubbling implies that a chemical change has taken place.
For chemical changes to occur, we observe any of the following:
- a new kind of matter is formed.
- it is always accompanied by energy changes
- the process is not easily reversible
- it involves a change in mass
- requires considerable amount of energy.
ii. Two signs that shows a chemical change has taken place is that:
- bubbles are being formed as it is roasted and it implies that new substances have been formed.
- also, significant amount of heat energy is supplied for the roasting.
Answer:
0.719M AgNO₃
Explanation:
Based on the reaction:
MgBr₂ + 2AgNO₃ ⇄ 2AgBr + Mg(NO₃)₂
<em>1 mole of magnesium bromide reacts completely with 2 moles of AgNO₃</em>
<em />
To find molarity of AgNO₃ solution we need to determine moles of AgNO₃ and, as molarity is the ratio of moles over liter (13.9mL = 0.0139L). Now, to determine moles of AgNO₃ we need to use the reaction, thus:
<em>Moles AgNO₃:</em>
<em />
Moles of MgBr₂ are:
50.0mL = 0.050L * (0.100mol / L) = 0.00500 moles of MgBr₂.
As the silver nitrate reacts completely and 2 moles of AgNO₃ reacts per mole of MgBr₂:
0.00500 moles MgBr₂ * (2 moles AgNO₃ / 1 mole MgBr₂) =
0.0100 moles of AgNO₃ are in the solution.
And molarity is:
0.0100 moles AgNO₃ / 0.0139L =
<h3>0.719M AgNO₃</h3>
