Four students give their teacher identical apples. Each student sets his or her apple on a different stack of books. Which

31.5 grams of an unknown substance is heated to 102.4 degrees Celsius and then placed into a calorimeter containing 103.5 grams

Alexxandr [17]

Heat gained in a system can be calculated by multiplying the given mass to the specific heat capacity of the substance and the temperature difference. It is expressed as follows:<span>

Heat = mC(T2-T1)

When two objects are in contact, it should be that the heat lost is equal to what is gained by the other. From this, we can calculate things. We do as follows:

</span>Heat gained = Heat lost
mC(T2-T1) = - mC(T2-T1)
31.5C (102.4 - 32.5) = 103.5(4.18)(32.5 - 24.5)
C = 1.57 J/C-g

Hope this helps.

5 0

3 years ago

Which substance is insoluble and floats in water? A) Ice shavings B) Wood shavings C) Salt crystals D) Sugar crystals

saw5 [17]

Answer: B) Wood Shavings

Reason/Explanation:
Notice what options A, C, and D have on common. Ice, salt and sugar. Those are all dissolvable. Insoluble means un-able to dissolve. It can't dissolve. Wood shavings can't dissolve in water. They will just float. Sugar, salt and ice will all dissolve. Wood shavings won't.

-DustinBR

8 0

3 years ago

Read 2 more answers

How strong are bonds between subatomic particles?

Aleks [24]

Answer:

they are indeed very strong

8 0

3 years ago

Does potassium nitrate (KN03) incorporate ionic bonding, covalent bonding, or both? Explain.

ladessa [460]

Answer: $KNO_3$ incorporates both ionic bonding and covalent bonding.

Explanation:

A covalent bond is formed when an element shares its valence electron with another element. This bond is formed between two non metals.

An ionic bond is formed when an element completely transfers its valence electron to another element. The element which donates the electron is known as electropositive element and the element which accepts the electrons is known as electronegative element. This bond is formed between a metal and an non-metal.

For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.

Here potassium is having an oxidation state of +1 called as $K^{+}$ cation and nitrate $NO_3^{-}$ is an anion with oxidation state of -1. Thus they combine and their oxidation states are exchanged and written in simplest whole number ratios to give neutral $KNO_3$ . $NO_3^-$ is formed by sharing of electrons between two non metals nitrogen and oxygen.