Answer:
A calculator has an endifiite shape because all of its atoms are touching each other
<h3>
Answer:</h3>
3CaCl₂ + 2Na₃PO₄→ Ca₃(PO₄)₂ + 6NaCl
<h3>
Explanation:</h3>
We are given the Equation;
CaCl₂ + Na₃PO₄→ Ca₃(PO₄)₂ + NaCl
Assuming the question requires us to balance the equation;
- A balanced chemical equation is one that has equal number of atoms of each element on both sides of the equation.
- Balancing chemical equations ensures that they obey the law of conservation of mass in chemical equations.
- According to the law of conservation of mass in chemical equation, the mass of the reactants should always be equal to the mass of the products.
- Balancing chemical equations involves putting appropriate coefficients on the reactants and products.
In this case;
- To balance the equation we are going to put the coefficients 3, 2, 1, and 6.
- Therefore; the balanced equation will be;
3CaCl₂ + 2Na₃PO₄→ Ca₃(PO₄)₂ + 6NaCl
Answer:
a) the minimun of acetic anhydride required for the reaction is 2.175 g (CH3CO)2O
b) V acetic anhydride = 2.010 mL
Explanation:
C6H4OHCOOH + (CH3CO)2O ↔ C9H8O4 + C2H4O2
⇒ mol salicylic acid = 2.94 g C6H4OHCOOH * ( mol C6H4OHCOOH / 138.121 g ) = 0.0213 mol C6H4OHCOOH
⇒ mol acetic anhydride = 0.0213 mol C6H4OHCOOH * ( mol (CH3CO)2O / mol C6H4OHCOOH ) = 0.0213 mol (CHECO)2O
⇒ g acetic anhydride = 0.0213 mol * ( 102.1 g/mol ) = 2.175 g CH3CO)2O
b) V = 2.175 g (CH3CO)2 * ( mL / 1.082 g ) = 2.010 mL (CH3CO)2O
The pH of the solution : 12
<h3>Further explanation</h3>
Reaction
HCOOH + NaOH ⇒ HCOONa + H₂O
mol HCOOH =
mol NaOH =
Mol NaOH>mol HCOOH ⇒ at the end of the reaction there will be a strong base remains from mol NaOH, so that the pH is determined from [OH⁻]
ICE method :
HCOOH + NaOH ⇒ HCOONa + H₂O
4 5
4 4 4 4
0 1 1 1
Concentration of [OH⁻] from NaOH :
pOH=-log[OH⁻]
pOH=-log 10⁻²=2
pH+pOH=14
pH=14-2=12
Answer:
A
Explanation:
Sodium has 11 electrons and Magnesium has 12 electrons. Since here you need to consider atoms, they must have equal amount of protons as electrons to be considered neutral, and so an atom.
So simply 11+12 =23