Answer:
The mass of the products left in the test tube will be less than that of the original reactants.
Explanation
The equation for the reaction is
Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)
1.0 3.0 3.9 0.1
Assume you started with 1.0 g of Mg.
It will react with 3.0 g of HCl to form 3.9 g of MgCl2 and 0.1 g of H2
.
Mass of reactants = mass of products
1.0 g + 3.0 g = 3.9 g + 0.1 g
4.0 g = 4.0 g
The Law of Conservation of Mass is obeyed.
However, your test tube and its contents will weigh 0.1 g less than it did before the reaction.
Does that contradict the Law of Conservation of Mass? It does not.
One of the products was the gas, hydrogen, and it escaped from the test tube. You weren't measuring all the products, so test tube and its contents weighed less than before.
Answer:
2.13 V
Explanation:
The balanced equation of the reaction his;
2Cr^3+(aq) + 3Ca(s) -----> 2Cr(s) + 3Ca^2+(aq)
Since this is a galvanic cell then E°cell must be positive. It implies that calcium will be the anode and chromium will be the cathode since calcium is ahead of chromium in the electrochemical series.
E°anode= -2.87 V
E°cathode= -0.74 V
E°cell= E°cathode -E°anode
E°cell= -0.74 -(-2.87)
E°cell = 2.13 V
<span>1) Boiling water for pasta-> physical
2) Digesting food -> chemical
3) Soda goes "flat" -> physical
4) Stretching a rubber band -> physical
5) Grilling a hamburger -> chemical
6) Adding sugar to tea -> physical
7) Adding lemon to tea -> physical
8) Mowing the grass -> physical
9) The smell of perfume "wafts" across the room -> physical
10) Candle wax melts -> physical
11) Breaking glass-> physical
12) Making cement-> chemical
13) Lighting a match-> chemical
14) Water is absorbed by a paper towel-> physical
15) Firefly glows in the dark-> chemical
16) Snow melts-> physical
17) Bleaching your hair-> chemical
18) Turning on a light bulb-> physical
19) Milk goes sour-> chemical
20) Shooting off fireworks-> chemical</span>
Answer:
The element is Dysprosium.
Hydrogen??????????????????????
