Answer:
It keeps us alive, helps us grow plants, helps plants thrive, gives us food, helps keep our animals and crops healthy, cleans us, and so much more
Explanation:
Percentage by mass is the mass of NaF present in 100 g of the solution.
the percentage by mass of NaF is 23.4 %
this means that in 100 g of solution, mass of NaF present is 23.4 g
the number of moles of NaF present - 1.33 mol
mass of NaF - 1.33 mol x 42 g/mol = 55.9 g
when there's 23.4 g of NaF - mass of solution is 100 g
therefore when there's 55.9 g of NaF - mass of solution is 100 / 23.4 x 55.9
= 239 g
mass of solution required is 239 g
Answer:
See explanation
Explanation:
Let us look at the reaction again;
Cr2O7 2- (aq) + H2O(l)⇄ 2CrO4 2-(aq) + 2H^+(aq)
When we add sodium hydroxide to the system as shown, the hydroxide ion removes the hydrogen ion thereby leaving a large concentration CrO4^2-(aq) in the system this causes the solution to turn green(equilibrium position shifts to the right).
The net ionic equation is;
OH^-(aq) + H^+(aq) ----> H2O(l)
The reaction;
OH^-(aq) + H^+(aq) ----> H2O(l) is exothermic hence, if the temperature of the system is increased, the equilibrium position will shift towards the left hand side and the solution turns orange.
Answer:
net force is 100 N and direction is right
Explanation:
Answer: The initial temperature of the iron was 
Explanation:
As we know that,
![m_1\times c_1\times (T_{final}-T_1)=-[m_2\times c_2\times (T_{final}-T_2)]](https://tex.z-dn.net/?f=m_1%5Ctimes%20c_1%5Ctimes%20%28T_%7Bfinal%7D-T_1%29%3D-%5Bm_2%5Ctimes%20c_2%5Ctimes%20%28T_%7Bfinal%7D-T_2%29%5D)
.................(1)
where,
q = heat absorbed or released
= mass of iron = 360 g
= mass of water = 750 g
= final temperature = 
= temperature of iron = ?
= temperature of water = 
= specific heat of iron = 
= specific heat of water= 
Now put all the given values in equation (1), we get
![-360\times 0.450\times (46.7-x)=[750\times 4.184\times (46.7-22.5)]](https://tex.z-dn.net/?f=-360%5Ctimes%200.450%5Ctimes%20%2846.7-x%29%3D%5B750%5Ctimes%204.184%5Ctimes%20%2846.7-22.5%29%5D)
Therefore, the initial temperature of the iron was
