Answer:
The reaction between the salt and water is endothermic
Explanation:
An endothermic reaction is one that absorbs heat from the surrounding creating a kind of coldness in the immediate environment of the reaction. The direct opposite of endothermic reaction is exothermic reaction, a reaction that dissipates heat to the immediate surrounding of the reaction.
Commercial cold packs works based on the principle of endothermic reaction. The packs are usually made up of water and ammonium nitrate salts isolated by easily breakable barriers. The dissolution of ammonium nitrate salts in water is generally endothermic.
In order to make use of the cold pack, a force needs to be applied to the pack in order to break the barrier separating the water and the ammonium salt. The water-ammonium salt mixture creates an endothermic reaction which immediately lowers the temperature of the resulting solution to about 35 F for a period of 10 to 15 minutes.
Answer:
The correct answer is 101 feet.
Explanation:
To solve this problem, we need to remember the rules of significant figures. Any digit that is not zero is significant, and any zero is significant if it is between two non-zero digits or a trailing zero after the decimal point. Now, let's apply these rules to the options that are given:
1000 yards - Since the zeros are not after the decimal point or between two other digits, they are not significant. This means the only significant digit is 1, so there is only 1 significant digit.
1014 miles - All three of the non-zero digits are significant, and the 0 is significant in this case because it is between two other significant digits. Therefore, this number has 4 significant digits.
101 feet - The two 1's are significant because they are non-zero digits, and the zero is also significant because it is between the two 1's. Therefore, this number has 3 significant digits.
Thus, your answer is 101 feet.
Hope this helps!
Answer:
I am pretty sure that it is A. H2.
Explanation:
Sorry if it's wrong.
Answer:
A ,B- false
C,D- true
Explanation:
Dipole forces always lead to stronger attraction and boiling points than dispersion forces. When linear molecules are involved, they often posses greater dipole forces and higher boiling points. Linear alkanes posses higher boiling points than branched alkanes.
Answer: The volume for 0.850 mol of from a solution is 1700 mL.
The volume of 30.0 g of LiOH from a 2.70 M LiOH solution is 464 mL.
Explanation:
Molarity is the number of moles of solute present in a liter of solution.
- As given moles of are 0.850 mol and molarity of solution is 0.5 M. Hence, its volume is calculated as follows.
Therefore, the volume for 0.850 mol of from a solution is 1700 mL.
- As given mass of LiOH are 30.0 g from a 2.70 M LiOH (molar mass = 23.95 g/mol) solution. Hence, its number of moles are calculated as follows.
So, volume for LiOH solution is calculated as follows.
Therefore, volume of 30.0 g of LiOH from a 2.70 M LiOH solution is 464 mL.