Answer:
Specific gravity is the density of asubstance divided by the density of water. Since (at standard temperature and pressure) water has a density of 1 gram/cm3, and since all of the units cancel, specific gravity is usually very close to the same value as density(but without any units).
The average acceleration is -5.0 m·s⁻².
The formula for acceleration (<em>a</em>) is
= 25 m·s⁻¹; 
= 0; 
= 5.0 s
∴ 
= -5.0 m·s⁻²
The negative sign tells you that the object is <em>slowing down</em>, i.e., it is <em>decelerating</em>.
Answer:
0.78 atm
Explanation:
Step 1:
Data obtained from the question. This includes:
Mass of CO2 = 5.6g
Volume (V) = 4L
Temperature (T) =300K
Pressure (P) =?
Step 2:
Determination of the number of mole of CO2.
This is illustrated below:
Mass of CO2 = 5.6g
Molar Mass of CO2 = 12 + (2x16) = 12 + 32 = 44g/mol
Number of mole CO2 =?
Number of mole = Mass/Molar Mass
Number of mole of CO2 = 5.6/44
Number of mole of CO2 = 0.127 mole
Step 3:
Determination of the pressure in the container.
The pressure in the container can be obtained by applying the ideal gas equation as follow:
PV = nRT
The gas constant (R) = 0.082atm.L/Kmol
The number of mole (n) = 0.127 mole
P x 4 = 0.127 x 0.082 x 300
Divide both side by 4
P = (0.127 x 0.082 x 300) /4
P = 0.78 atm
Therefore, the pressure in the container is
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.
<span>Answer:
For this problem, you would need to know the specific heat of water, that is, the amount of energy required to raise the temperature of 1 g of water by 1 degree C. The formula is q = c X m X delta T, where q is the specific heat of water, m is the mass and delta T is the change in temperature. If we look up the specific heat of water, we find it is 4.184 J/(g X degree C). The temperature of the water went up 20 degrees.
4.184 x 713 x 20.0 = 59700 J to 3 significant digits, or 59.7 kJ.
Now, that is the energy to form B2O3 from 1 gram of boron. If we want kJ/mole, we need to do a little more work.
To find the number of moles of Boron contained in 1 gram, we need to know the gram atomic mass of Boron, which is 10.811. Dividing 1 gram of boron by 10.811 gives us .0925 moles of boron. Since it takes 2 moles of boron to make 1 mole B2O3, we would divide the number of moles of boron by two to get the number of moles of B2O3.
.0925/2 = .0462 moles...so you would divide the energy in KJ by the number of moles to get KJ/mole. 59.7/.0462 = 1290 KJ/mole.</span>
