Mr Rayon

If a piece of zinc metal is added to the following solutions, will a reaction be expected? If so, write the equation for the reaction. a AlCl3 b AgNO3 c SnCl2 d CuSO4 In my textbook it says the answers are: A33. a no - but why? b Zn(s) + AgNO3(aq) ---> Zn(NO3)2(aq) + Ag(s) - the NO3 isn't balanced here! c Zn(s) + SnCl2(aq) ---> ZnCl2(aq) + Sn(s) - why is it that the Cl2 reacts with Zn and not Sn? d Zn(s) + CuSO4(aq) ---> ZnSO4(aq) + Cu(s) - why is it that SO4 reacts with Zn but not Cu in CuSO4?

You are given three colourless solutions (A, B and C) known to be sodium nitrate, silver nitrate and lead nitrate but not necessarily in this order. You also have some pieces of magnesium ribbon and copper wire. Describe how you could identify each of the solutions using only the chemicals supplied.

I'm a high-school student. Anyone got any other bright ideas?

My class has spent several weeks on making a student designed practical experiment and unfortunately due to illness I have been away. Does anyone know of any good experiments that can be conducted in a classroom involving motion, particularly to prove the effect of safety features in cars? Or if not this, than just of any experiments involving motion? I haven't started at all and can't think of anything (complete mental blank), it seems as though physics is too demanding of a subject and impossible to apply the theory to practicals. Well, is anyone willing to prove me wrong? Anyone have any ideas?

The mass of AgNO3 dissolved in 300 g of water in a beaker and then heated to 50°C is: A) 152 g. B) 246 g. C) 455 g. D) 1365 g. How do you figure this out? Can anyone help or perhaps provide complete working out?

Which of the follwoing is not a property of water? A) Water readily dissolves many ionic salts. B) Water boils at 100 degrees celcius. C) Water has a relatively high surface tension. D) Water is colourless and odourless.

Which of the following alternatives contains only water soluble substances? A) Potassium chloride (KCl), and (SiO2), ammonia (NH3). B) Sodium nitrate (NaNO3), and glucose (C6H12O6), hydrogen chloride (HCl). C) Barium hydroxide (Ba(OH)2), salt (NaCl), ethane (C2H6). D) Iron (II) oxide (FeO), ethene (C2H4), ethanol (C2H5OH). I am confused! I do not know how to work this out...I don't think we have even covered this in class. How do you know what the answer is? Could somebody elaborate please on how you got the answer?

A car travelling with a constant speed of 80 km/h passes a stationary motorcyle policeman. The policeman sets off in pursuit, accelerating to 80 km/h in 10.0 s and reaching a constant speed of 100km/h after a further 5.0 s. At what time will the policeman catch up with the car? Any help for the above problem will be appreciated!

No, it's my homework.

Please respond in less than one hour.

What techniques are used to assist the host to survive or resist the disease? If I were to say by surgical removal of the cysts in the body, would that be sufficient? I'm not sure how else the host would resist this disease...By the way, hydatids is caused by echinoccoccus granulosus (a taperworm).

EDIT 2: Was Dolly the sheep created using stem cell research? EDIT 3: Did she die earlier than the average sheep? Were there any remarkable and noticeable differences between Dolly and other sheep? Nevermind...Dolly died at the age of six which was half of the life-expectancy of ordinary sheep. I have also found out that straight after Dolly had been created, other animals had been cloned also. Did they live to their life-expectancy? Or did they die early? And what about Dolly's offspring, are they still alive?

What is the general consensus?

So, just to clarify adult stem cell research as well other types of stem cells (apart from embryonic) are not considered to be wrong? Merged post follows: Consecutive posts mergedIf adult stem cell research is considered okay, why not just conduct adult stem cell research instead of embryonic stem cell research?

In what ways do the bonding and molecular shape determine the polarity of a molecule?

...out of curiosity, in a molecule, how does the polarity of a molecule determine the type of intermolecular force present?

Methane (CH4), ammonia (NH3), water (H2O), hydrogen chloride (HCl), butane (C4H10), phosphine (PH3), oxygen (O2), carbon dioxide (CO2), ethene (C2H4), nitrogen (N2), ethyne (C2H2). And how do you know? Please someone respond in less than an hour!

Could you list the differences?

What are the pros and cons of stem cell research? I am supposed to form an argument about it tomorrow for an oral presentation for English. I am supposed to convince my class that I am right by using many persuasive techniques (e.g. bias). The oral is supposed to be 5 minutes long. What are the ethical issues of stem cell research? Thanks

What's everybody worried about?

Is it more correct to say the HIV or the HIV virus?

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All proteins contain carbon, hydrogen, oxygen and nitrogen. In addition to these, some also contain sulfur and phosphorus. I'm still not sure. I guess, C, H, O and N. But that still leaves B and D.

The formula that represents a protein is compound A. C18H32O2 B. C58H114PNO8 C. C600H1000O500 D. C708H1130N180O224S4 The answer is D. Please explain why B is not a good answer.

The drift velocity is directly proportional to the current in the conductor. If electrons have a drift velocity of 1.6*10^-4 m s^-1 for a current of 10 A in a certain conductor, what would be their velocity if the current was 5.0 A? What is drift velocity by the way? Any help on the above will be appreciated!