science questions!?

Question

i am a bit puzzled with some of them. can you help?

1,if you mix bicarbinate of soda with lemon juice, how could you tell that a gas was produced?

2,if you have a copper rod and you fixed one end of the rod and allowed the other to roll on a pin to show the movement of the rod, what happens to the motion of the copper atoms when the rod is heated?

2b,what happens to the average difference between the atoms of copper when the rod is heated?

3,a footballer is just going to kick the ball. when his boot hits the ball,how does the shape of the ball change?

thanks for your help!

p.s. if you dissolved bicarbinate of soda in distilled water, what colour would it be on the universal indicator?

Answer 1

1. Mix them in a non-deformable container with a small opening. The gas production should be macroscopically detectable. (Put your hand over the hole.)
2."rolling on a pin" is not a good description of anything in this context. (I have no idea what you might be talking about.)
The Cu atoms will vibrate faster when heated.
2b. The average difference between the atoms of copper increases when the rod is heated.
3. The ball deforms, the internal pressure increases, and the size increases slightly and momentarily .
p.s. The universal ph indicator should turn blue if not purple.

Answer 2

1. place a lighted match over the opening of the container after the two substances are mixed. Carbon dioxide will be produced which will snuff out the match.

2. Not sure about your description but anytime matter is heated, the atoms gain thermal energy which will cause the motion of the atoms to increase.

3. Average difference of what?

4. At the point of contact, the surface of the ball will cave in as the boot pushes into the ball.

Answer 3

PS / bicarbonate of soda (sodium bicarbonate (NaHCO3)
http://en.wikipedia.org/wiki/Sodium_bicarbonate
says a solution in water is "mildly alkaline"

3/ How the shape of the ball changes will depend on how heavy the ball is, how hard it is pumped-up, how 'squishy' the footballer's boot is, whether kicked with toe/instep/outer, where on the ball it was kicked and how fast it was kicked. Go kick a football a few times and write down what you think happens.

2/ a and b , you heat the rod - it gets longer, the number of atoms in the rod doesn't change, the rod doesn't get thinner.

1/ look at it, it fizzes.

Answer 4

1. you could light a match and hols it in the glass/ container. . . . .the match would be extinguished and would prove the presence of carbon dioxide (co2)
2. the rod expands for one thing and it would also start to spin because on heating the atoms gain energy and this causes them to move faster and also reduces the time period between collisions . . . . . .
2b. no difference . . . .just the increase in momentum
3. the ball compreses at the position of contact and this pressurises the ball as a whole and causes the other side to expand and thus the ball looks oblate. . . .

Answer 5

3) the ball also heats up ever so slightly!