Answer:
1.5 M.
Explanation:
- Molarity (M) is defined as the no. of moles of solute dissolved in a 1.0 L of the solution.
<em>M = (no. of moles of LiBr)/(Volume of the solution (L).</em>
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∵ no. of moles of LiBr = (mass/molar mass) of LiBr = (97.7 g)/(86.845 g/mol) = 1.125 mol.
Volume of the solution = 750.0 mL = 0.75 L.
∴ M = (no. of moles of luminol)/(Volume of the solution (L) = (1.125 mol)/(0.75 L) = 1.5 M.
The correct answers are as follows:
1. Aluminium will not be useful as food wrapping if it has a much lower melting point.
Aluminum is a metallic element that is malleable and soft, thus, it is easy to beat it into thin sheet, which are used to package food. The thin sheet is called aluminium foil. Aluminum is useful as a food wrapping because it has high temperature and thus, it does not react with food (the hotness of the packaged food is not capable of melting the metal). If the melting point of aluminium is lower, this implies that little temperature, such as the one from hot food will be able to melt aluminum foil, thus allowing the food to be contaminated with the metal.
2. When bleach react with fabric dye chemical change occur in the fabric.
The major element in bleach is chlorine. When laundry bleach is added to a fabric, the chlorine component of the bleach will react with the fabric dye and cause a colour change in the fabric. This type of change is called chemical change, because the original colour of the fabric can not be recovered.
3. Every substance has specific properties, which can be used to identify it. Two of such specific properties are melting point and boiling point. Melting point refers to a specific temperature at which a solid substance will melt while boiling point refers to a specific temperature at which a liquid substance will boil and turn to steam.
Water for instance has a boiling point of 100 degree Celsius. To find out if an unknown substance is water, one can determine the boiling point of such liquid. A boiling point of 100 degree Celsius will strongly signify that the substance is probably water. The same thing applies to melting point. If the specific boiling and melting point of substances are known, then they can be used to identify them.
Of course we would experience them.
Answer: when the temperature is increased, the number of collisions per second increases.
Explanation:
the rate of collisions and the temperature is directly proportional. If the energy of the gas particles is boosted by using the temperature, the chances of the particles bumping into each other due to the high energy increases, thus increasing the number of collisions. This also increases the rate of reaction. Thus when temperature is increased the number of collisions also increases.
