Answer:
96.5 grams is the mass of the silver block.
Step-by-step explanation:
Heat lost by iron will be equal to heat gained by the water
![-Q_1=Q_2](https://img.qammunity.org/2020/formulas/chemistry/high-school/x4d84844cf7v8n3zxfk5ayic59m7m9de2g.png)
Mass of iron =
![m_1=?](https://img.qammunity.org/2020/formulas/chemistry/high-school/1uc99lvxh98drtjkml1x0s4rx7pf4z4i0g.png)
Specific heat capacity of silver=
![c_1=0.240 J/g^oC](https://img.qammunity.org/2020/formulas/chemistry/high-school/n37hn6k74azu50d70o8tw4dlphe7moiwso.png)
Initial temperature of the silver=
![T_1=120^oC](https://img.qammunity.org/2020/formulas/physics/high-school/r58uv3qkq1cvrcg9exewp3u1u3my5b1jvh.png)
Final temperature =
![T_2=T=26.5^oC](https://img.qammunity.org/2020/formulas/chemistry/high-school/24jmu4s39olzx0rxfyt9hm4sm20qmam43j.png)
![Q_1=m_1c_1* (T-T_1)](https://img.qammunity.org/2020/formulas/chemistry/high-school/bw124kr4z3n5i7xnl9mopmpuvecxtj78ru.png)
Mass of water=
![m_2=100.0 g](https://img.qammunity.org/2020/formulas/chemistry/high-school/ik0rx04y5zcoa3w51cqzgm83enllsmzun4.png)
Specific heat capacity of water=
![c_2=4.184 J/g^oC](https://img.qammunity.org/2020/formulas/chemistry/college/as2c4hfo088x9ypx7u07rnnxkacevclkfm.png)
Initial temperature of the water =
![T_3=24.8 ^oC](https://img.qammunity.org/2020/formulas/chemistry/high-school/oi01a485m9d7vmfbxhjutkebhx3emcxbjm.png)
Final temperature of water =
![T_2=T=26.5^oC](https://img.qammunity.org/2020/formulas/chemistry/high-school/24jmu4s39olzx0rxfyt9hm4sm20qmam43j.png)
![Q_2=m_2c_2* (T-T_3)](https://img.qammunity.org/2020/formulas/chemistry/high-school/z8q7q9gkkkrhh8mvyfxthbpttdiutgwj6f.png)
![-Q_1=Q_2](https://img.qammunity.org/2020/formulas/chemistry/high-school/x4d84844cf7v8n3zxfk5ayic59m7m9de2g.png)
![-(m_1c_1* (T-T_1))=m_2c_2* (T-T_3)](https://img.qammunity.org/2020/formulas/chemistry/high-school/f9xu0qrb6vxcugskudebhgpt1cy6lt2vtq.png)
On substituting all values:
![-(m_1* 0.240 J/g^oC* (26.5^oC-57.2^oC))=100.0 g* 4.184 J/g^oC* (26.5^oC-24.8^oC)](https://img.qammunity.org/2020/formulas/chemistry/high-school/mofrp9zvwfstat3fr6xwrw7ra5zz3hs9v9.png)
we get,
![m_1 = 96.5 g](https://img.qammunity.org/2020/formulas/chemistry/high-school/dxse4pk6ggkhqzzifu60f506j3m8aznepl.png)
96.5 grams is the mass of the silver block.