Answer:
B. Cu + 4HNO3 → Cu(NO3)2 + 2H2O + 2NO2
Explanation:
Hello,
In this case, we should understand oxidizing agents as those substances able to increase the oxidation state of another substance, therefore, in B. reaction we notice that copper oxidation state at the beginning is zero (no bonds are formed) and once it reacts with nitric acid, its oxidation states raises to +2 in copper (II) nitrate, thus, in B. Cu + 4HNO3 → Cu(NO3)2 + 2H2O + 2NO2 nitritc acid is acting as the oxidizing agent.
Moreover, in the other reactions, copper (A.), sodium (C. and D.) remain with the same initial oxidation state, +2 and +1 respectively.
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<u>Answer:</u> The molality of the solution is 0.11 m
<u>Explanation:</u>
We are given:
Mole fraction of methanol = 0.135
This means that 0.135 moles of methanol is present in 1 mole of a solution
Moles of ethanol = 1 - 0.135 = 0.865 moles
To calculate the mass for given number of moles, we use the equation:

Moles of ethanol = 0.865 moles
Molar mass of ethanol = 46 g/mol

To calculate the molality of solution, we use the equation:

Where,
= Given mass of solute (methanol) = 0.135 g
= Molar mass of solute (methanol) = 32 g/mol
= Mass of solvent (ethanol) = 39.79 g
Putting values in above equation, we get:

Hence, the molality of the solution is 0.11 m
D. Cell membrane: surrounds a cell and allows substances to pass in and out
Answer:
A
Explanation:
Cs has a higher rate of reaction because it's easier to remove an electron from it, thereby leading to faster reactivity
Answer:
The number of moles of Sr in one mole of Sr(HCO₃)₂ = 1 mole
The number of moles of H in one mole of Sr(HCO₃)₂ = 2 moles
The number of moles of C in one mole of Sr(HCO₃)₂ = 2 moles
The number of moles of O in one mole of Sr(HCO₃)₂ = 6 moles
Explanation:
The given chemical formula of the compound is Sr(HCO₃)₂
The number of atoms of Sr in the compound = 1
The number of atoms of H in the compound = 2
The number of atoms of C in the compound = 2
The number of atoms of O in the compound = 6
The number of atoms of each element present in each formula unit of Sr(HCO₃)₂ is proportional to the number of moles of each atom in one mole of Sr(HCO₃)₂
Therefore;
The number of moles of Sr in one mole of Sr(HCO₃)₂ = 1 mole
The number of moles of H in one mole of Sr(HCO₃)₂ = 2 moles
The number of moles of C in one mole of Sr(HCO₃)₂ = 2 moles
The number of moles of O in one mole of Sr(HCO₃)₂ = 6 moles.