why is the boiling point for SiO2 much higher than CO2 despite the fact they are in group 4 of periodic table?
970701
The reason why silica has a high melting point is that it forms a giant structure with the silicon is bound to four oxygen atoms in an arrangement similar to diamond (tetrahedrally) with the silicon atoms placed between the oxygen atoms. It does this because the SiO2 had a significantly larger ionic character than carbon dioxide.
861257
different chemicals have different boiling points. while some chemicals boil at a very high temp, others boil at a low temp. once a chemical hits its boiling point it turns to a gas. so carbon dioxide has a very low boiling point and therefore is a gas at a temperature that is comfortable for us.\n\nat least i think that's what i understood from my high school sience class.
30770
Excellent question.  Food for thought for both of us.  Let's see- changing the pH of water could allow for greater or less solubility of minerals.  With more minerals in solution, the rate of evaporation increases while the boiling/freezing point lowers, as intermolecular attraction is decreased.  The opposite would then be true with less minerals in solution.
1000171
They have full outter electron shells, so they are less reactive with other elemnets and they are all in the gas stage at room temperature. Hm, I think that's right. It's been a few years...
392846
The table is of the elements.  Carbon dioxide is not an element.
1187079
Boiling point depends on the strength of the intermolecular forces. Following is the list of them all with their strength and when they occur. \nnetwork covalent (strongest) with only diamond or SiO2\nIonic (ionic compound, 2nd strongest) like Na-Cl etc. Gets stronger with smaller sizes. \nHydrogen bonding (N, O, F with H) 3 rd strongest. \nDipole dipole (when there is a polar molecule) 4 th strongest, gets stronger with more polarity. \nLondon dispersion weakest. Stronger with more mass. \n\na NH3of the first two. Because NH3 has hydrogen bonding (only if you have N, O, or F with hydrogen) while PH3 has regular dipole dipole (based on polarity), which is weaker than NH3. \nNow in this one its c because if you draw their Lewis diagrams out c molecule has on O----H bond while d doesn't. That hydrogen bond is strong enough to make c stronger. As other than that they only have London dispersion force, (which are found in non polar molecules, and they get stronger as atomic mass gets higher). \ne and f both have the London dispersion force that I talked about earlier cause they both are non polar. So f has greater mass so f has higher boiling point. \ng because HCl has polarity (dipole dipole forces) which are stronger than F2 which is non polar and has London dispersion forces (they are the weakest).
1018878
Lithium boils at 1342 C.\nhttp://www.lenntech.com/Periodic-chart-elements/Li-en.htm
264077
Right off the bat without looking up anything, I would say CH4 has the lowest boiling point.  Why?  Well, it is the least complex molecule of them all.  Additionally, it is symmetric, therefore non polar.  Since it is the smallest and least complex, it really doesn't have a dipole-dipole interaction such as the other larger molecules, requiring either a lot more pressure to cause condensation or a removal of a lot of heat to really bring it to a low temperature.  Furthermore, there isn't any entanglements when two or more molecules collide, which the larger hydrocarbons are prone to because they have comparatively longer chains.
281476
Hi Krish_darwin, here is my answer to your problem ;)-\n\nFirst of all, we have to define what we mean by the thermal stability of a hydroxide, the thermal stability refers to that property of a hydroxide due to which, it resists its breakdown into its oxide and hydrogen i.e.\n\nMOH + Heat --------> M2O + H2\n\nAs we know that, in the 1st gp, as we move up, oxides are more stable because, the polarising power of the cation increases up the group.\n\nSo, that means that, as we move up, hydroxides become less stable and oxides become more stable. (see reaction)\n\nTherefore, we can say that thermal stability increases down the group.\n\nNow, coming to stability, as we know, lattice enthalpy decreases down the group, obviously, the stabilty of the hydroxide decreases down the group. Thus, this reaction can take place more easily down the group-\nMOH --------> M+     +     OH-
1162703
Higher. Boiling point is reached when the vapour pressure of the liquid is equal to the outside pressure. At sea -level boiling point of water is 100 C. So below sea level, since the air pressure is greater, boiling point is higher than 100 C
941271
KCl will have higher boiling point because its bond is polar.This can arise the posiibility of dipole-dipole interaction.Main factor which is determines boiling point is intermolecular forces.
834078
Well evaporation is some of the answer, but it largely depends on the specific reaction you are considering...some gases are more readily dissolved in liquid...temp and atmospheric pressure play a part.  You need to ask a more specific question...elements behave differently according to critical states...is not a black and white question
615100
the same elements except that \n-the ammount of CO2 inceases to 4%(not certain about the value)\n-the oxygen ammount decreeases to 16%\n-the water vapour ammount also increases
975427
1) O(2) = dioxide\n\n2) SeF(6) = selenium hexafluoride\n\n3) Si(2)Br(6) = disilicon hexabromide\n\n4) SCl(4) = ? sulfur tetrachloride\n\n5) CH(4) = carbon tetrahydrogenide\n\n6) B(2)Si = diboron silicide\n\n7) NF(3) =nitrogen trifluoride\n\ni just learned that today they might not all be right
337603
Here is the answer.. Just remember periodi table...\nElements on left most side are electro positive and elements on right most are electro negative. (The last row is nobel gases..so leave it)\nNow Cl- belongs to right most side... its more electro-ve\nRb, Ca are on left side.... they are electro positive(They will give  electron with out much force)\nSi, S are in middle-- their properties are in between...\n\nThats it!
209192
Boiling Point: \n204C (399F) \nMelting Point: \n100C (212F) \n\nCHECK IT OUT BUT I THINK ITS CORRECT
116173
The position of the elements in the periodic table gives you clues about the valences of each element. Also, if you remember the formulae for familiar substances (like carbon dioxide, water, sulfur dioxide, hydrochloric acid, etc) that will also give you clues about possible or likely valences. \n\nThe final answer is:\n\nmemorize.