Answer:
THE HEAT NEEDED TO CHANGE 3KG OF WATER FROM 10 C TO 80 C IS 877.8kJ OR 877,800 J.
Explanation:
Mass = 3.0 kg = 3 * 1000 = 3000 g
Initial temperature = 10 C
Final temperature = 80 C
Change in temperature = 80 - 10 = 70 C
Specific heat of water = 4.18 J/g C
Heat needed = unknown
Heat is the amount of energy in joules needed to change a gram of water by 1 C.
Heat = mass * specific heat * change in temperature
Heat = 3000 g * 4.18 J/g C * 70 C
Heat = 877 800 Joules
Heat = 877.8 kJ.
The heat needed to change 3 kg mass of water from 10 C to 80 C is 877,800 J or 877.8 kJ.
<u><em>Answer:</em></u>
<u><em>Explanation:</em></u>
Phosphate ion has covalent bond. As we known , covalent bond is formed by sharing of electrons between two atoms. As in this case, P form three single covalent bond with three oxygen atoms and one double covalent bond with one oxygen . The formal charges is -3.
While He is present in mono atomic form
NaI have ionic bond which is formed by donating electrons from one atom and other accept.
Ag is present independently with no other atom.
<u>Answer:</u> The given example is a physical change.
<u>Explanation:</u>
A chemical change is defined as the change in which chemical composition of a substance changes and results in the formation of a new substance. These are usually irreversible process.
A physical change is defined as the change in which only the shape and size of the substance changes and no new substance is formed. Only phase change occurs in these processes. These are usually considered as a reversible change.
For the given example: Moisture in the air forms beads of water on a cold window pane.
This is a physical change because water was initially present in the gaseous state (Moisture in the air) and when it is coming in contact with the cold window pane, the gaseous state of water gets converted into a liquid state.
Hence, the given example is a physical change.
Answer:
1 is the same 3 is pure substance 4 is different
Explanation:
not sure about 2
Hello!
The
dissociation reaction of HNO₃ is the following:
HNO₃ → H⁺ + NO₃⁻This is a strong acid, so the concentration of HNO₃ would be the same as the concentration of H⁺. The formula for pH is the following:
![pH=-log([H_3O^{+}])=-log(0,75M)=0,12](https://tex.z-dn.net/?f=pH%3D-log%28%5BH_3O%5E%7B%2B%7D%5D%29%3D-log%280%2C75M%29%3D0%2C12)
So, the pH would be
0,12Have a nice day!