Answer:
0.11mol/dm³
Explanation:
The reaction expression is given as:
HCl + NaOH → NaCl + H₂O
Volume of acid = 25cm³ = 0.025dm³
Volume of base = 18.4cm³ = 0.0184dm³
Concentration of base = 0.15mol/dm³
Solution:
The concentration of hydrochloric acid = ?
To solve this problem, let us first find the number of moles of the base;
Number of moles = concentration x volume
Number of moles = 0.15mol/dm³ x 0.0184dm³ = 0.00276mol
From the balanced reaction equation;
1 mole of NaOH will combine with 1 mole of HCl
Therefore, 0.00276mol of the base will combine with 0.00276mol of HCl
So;
Concentration of acid = 
= 
= 0.11mol/dm³
Answer:
Gold and copper are example of alloy
Explanation:
The average atomic mass of the element is the sum of the products of the percentage abundance of isotope and its mass number. Therefore, for atomic mass equal to 58.933, the most abundant isotope is cobalt-59. Thus, the answer is letter C.
It's the person that you in love with.<span />
A molecule that has a central atom surrounded by three single bond pairs and one unshared pair would have a trigonal pyramidal shape. The electon arrangement of this is called tetrahedral. It involves one atom located at the apex and at the corners are three atoms with a trigonal base. An example would be ammonia or NH3. Nitrogen has five valence electrons so that it needs to three more electrons to satisfy the octet rule and be stable. It would share electrons with the three nitrogen present. In order, to achieve the most stable geometry, the three atoms of hydrogen would attach with a bond angle of 109 degrees.
