1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
galina1969 [7]
3 years ago
14

Someone please help.

Chemistry
1 answer:
Yuri [45]3 years ago
6 0
17. ΔH rxn is the enthalpy of a reaction. It is the amount of energy or heat absorbed in a reaction. If enthalpy is positive, it means the reaction absorbs heat, which means it is endothermic. If the enthalpy is negative, it means the reaction release heat, which means it is exothermic.

18. yes, it is possible in theory but it is not necessary. Water is the ideal, cheaper, and most abundant liquid for a calorimeter. 

19. Specific heat= heat/mass*Temp. the mass is already known You can place the piece of metal in a calorimeter filled with water. the piece of metal and water must be at different temperatures. Ideally, you would heat up the water and let it cool down. This change in temperature in the temperature that goes into the formula for the piece of metal. The only missing value is the heat which can be easily calculated because water' specific heat is known which can be used to calculate the heat loss by the water, which is the same as the heat gain by the piece of metal. With all the three values calculated and measured, you can simply plug them into the formula and solve for the specific heat of the metal. 
You might be interested in
An objects volume can be found by adding its mass by its?
Inessa05 [86]
Volume* density=MASS
4 0
3 years ago
9) All elements can be sorted into 3 simple groups:
serious [3.7K]

Answer: B) metals, non-metals, metalloids

An example of a metal is iron. A non-metal example is oxygen, which is a gas at STP (standard temperature and pressure).

A metalloid is a bit of a mix between a metal and non-metal element. It's sorta like an element that has both properties of metals and non-metals, or it's in a murky gray area. An example of a metalloid would be silicon.

6 0
2 years ago
Read 2 more answers
Mohr's salt is a pale green crystalline solid which is soluble in water. It is a 'double sulfate' which contains two cations, on
Veronika [31]
The gas is NH₃.
H₂ doesn't dissolve readily in water, SO₂ gives an acidic solution in water.

The solid residue is Fe(OH)₂.
FeSO₄ and Na₂SO₄ are soluble in water.

The answer is C.
3 0
3 years ago
30.0 ml of an hf solution were titrated with 22.15 ml of a 0.122 m koh solution to reach the equivalence point. what is the mola
a_sh-v [17]
Answer is: molarity of hydrofluoric solution is 0.09 M.

Chemical reaction: HF(aq) + KOH(aq) → KF(aq) + H₂O(l).
V(HF) = 30.0 mL.
c(KOH) = 0.122 M.
V(KOH) = 22.15 mL:
c(HF) = ?.
From chemical reaction: n(HF) : n(KOH) = 1 : 1.
n(HF) = n(KOH).
c(HF) · V(HF) = c(KOH) · V(KOH).
c(HF) = c(KOH) · V(KOH) ÷ V(HF).
c(HF) = 0.122 M · 22.15 mL ÷ 30 mL:
c(HF) = 0.09 M.
8 0
3 years ago
Read 2 more answers
Paul has different spoons for cooking. He told Sue that he likes to stir hot food with a wooden spoon because it does not burn h
IceJOKER [234]

Answer:

Sue was not right as wood is not a heat conductor and will not allow heat to pass through the spoon thus keeping the hand safe. In a meatal spoon, heat can pass through and burn the hand as meatal is a good conductor of heat.

8 0
3 years ago
Other questions:
  • True/False: A neutral atom contains the same number of protons as electrons
    10·2 answers
  • 74) A solution is prepared by dissolving 0.60 g of nicotine (a nonelectrolyte) in water to make 12 mL of solution. The osmotic p
    5·1 answer
  • A particular sample of air is 2.5% water vapor express the concentration of water vapor in parts per million
    6·1 answer
  • How can you determine if a reacition is exothermic?
    7·1 answer
  • An atom with 19 protons and 18 neutrons is a(n)
    12·1 answer
  • What is the molecular formula for a compound with an empirical formula of C2OH4 and a molar mass of 88 grams per mole
    13·1 answer
  • List 2 everyday situations in which it would be useful to identify unknown substances.
    14·1 answer
  • An ion from a given element has 38 protons and 36 electrons what is the charge
    8·1 answer
  • How many number of atoms does these have?
    7·1 answer
  • In a heat engine, 500 J of heat enters the system, and the piston does 300 J of work. What is the final internal (thermal) energ
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!