Answer: Attractive forces between particels
Explanation:
<u>Answer:</u> The amount of heat required to warm given amount of water is 470.9 kJ
<u>Explanation:</u>
To calculate the mass of water, we use the equation:

Density of water = 1 g/mL
Volume of water = 1.50 L = 1500 mL (Conversion factor: 1 L = 1000 mL)
Putting values in above equation, we get:

To calculate the heat absorbed by the water, we use the equation:

where,
q = heat absorbed
m = mass of water = 1500 g
c = heat capacity of water = 4.186 J/g°C
= change in temperature = 
Putting values in above equation, we get:

Hence, the amount of heat required to warm given amount of water is 470.9 kJ
A. As pressure on the gas increases, the volume and temperature will both decrease
Answer:
The elements in same period have same principle quantum number or energy shell.
The elements in same group shows similar chemical and properties.
Explanation:
Inn group:
The elements in same group i.e present in vertical column shows similar chemical properties.
The elements in same group having same number of valance electrons. while in chemical reaction bonds are break and formed and valance electrons are involved. That's why elements in same group having same number of valance electrons and shows similar chemical properties.
In period:
While as we move from left to right the number of valance electron increase by one in every element. But the electron is added in same shell which means that their physical and chemical properties are different but principal quantum number is same.
Explanation:
According to the Henderson-Hasselbalch equation, the relation between pH and
is as follows.
pH = 
where, pH = 7.4 and
= 7.21
As here, we can use the
nearest to the desired pH.
So, 7.4 = 7.21 + 
0.19 = 
= 1.55
1 mM phosphate buffer means
+
= 1 mM
Therefore, the two equations will be as follows.
= 1.55 ............. (1)
+
= 1 mM ........... (2)
Now, putting the value of
from equation (1) into equation (2) as follows.
1.55
= 1 mM
2.55
= 1 mM
= 0.392 mM
Putting the value of
in equation (1) we get the following.
0.392 mM +
= 1 mM
= (1 - 0.392) mM
= 0.608 mM
Thus, we can conclude that concentration of the acid must be 0.608 mM.