C is the answer it’s not d because mackerel does not eat tuna I’m not sure tho
1. Convert 135g Fe2O3 to moles, divide by 2, and multiply the resulting number by the molar mass of Al
The number of atoms of K that are in 235 g of the compound is
2.57 x10^24 atoms
calculation
Step 1: find the moles of K2S
= moles = mass/molar mass
= 235 g/110 g/mol= 2.136 moles
Step 2: multiply 2.136 moles by no. of K atoms in K2S
= 2.136 x2 = 4.272 moles
Step 3: use the Avogadro's law to determine number of K atoms
that is according to Avogadro's law 1 mole = 6.02 x 10^23 atoms
4.272 moles= ? atoms
by cross multiplication
= (4.272 moles x 6.02 x10^23 atoms) / 1 mole = 2.57 x10^24 atoms
Explanation:
- Evaporation is defined as a process in which liquid state of water is changing into vapor state.
So, we need to break the bonds of liquid substance in order to convert it into vapor state. And, energy is absorbed for breaking of bonds which means that evaporation is an endothermic process.
Hence, the statement evaporation of water is an exothermic process is false.
- When a hydrocarbon reacts with oxygen and leads to the formation of carbon dioxide and water then this type of reaction is known as combustion reaction.
A combustion reaction will always release heat energy. Hence, combustion reaction is exothermic in nature.
- When energy is transferred as heat from the surroundings to the system then it means energy is being absorbed by the system. And, absorption of heat is an endothermic process for which
is positive.
- Whereas when energy is transferred from system to the surrounding then it means energy is released by the system which is an exothermic process.
Hence, for an exothermic process value of
is negative.
Thus, we can conclude that statements which are true are as follows.
- A combustion reaction is exothermic.
- When energy is transferred as heat from the system to the surroundings,
is negative.
- For an endothermic reaction Deta H is positive.
i think helium hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh